Corporate Tax | Just Tax

C Corporation Tax Liability Computation (§§ 11, 291, 448)

This checklist computes a C corporation's regular income tax under § 11, applies the § 291 corporate preference adjustments, and determines the accounting-method and gross-receipts constraints under § 448. Use it when preparing or reviewing Form 1120 for any domestic C corporation.

Step 1. Taxable Income Computation Framework

"In the case of a corporation, the term taxable income means gross income minus the deductions allowed by this chapter." § 63(b).

• The C corporation taxable income formula. C corporations compute taxable income as gross income minus all allowable deductions. Unlike individual taxpayers, C corporations have no adjusted gross income, no standard deduction, and no personal exemptions. The computation proceeds directly from gross income to taxable income by subtracting business deductions. § 63(b). § 63(a) defines taxable income for individuals as adjusted gross income minus the standard deduction and personal exemptions. § 63(b) provides the parallel and much simpler rule for corporations.
• No AGI concept for C corporations. The statutory framework in § 63(a) defines taxable income for individuals as adjusted gross income minus itemized deductions. § 63(b) provides the parallel rule for corporations, omitting entirely the AGI computation layer. All deductions claimed by a C corporation are deducted below the line from gross income. Treas. Reg. § 1.63-1. This means that deductions for charitable contributions, interest expense, and all other business deductions are taken directly against gross income without any AGI-based percentage floors that apply to individual taxpayers.
• The Form 1120 computation path. The practical computation follows Form 1120 structure:
  • Start with gross receipts or sales
  • Subtract returns and allowances and cost of goods sold to arrive at gross profit
  • Add other income (dividends, interest, rents, royalties, net gain on asset sales, etc.)
  • Subtract deductions (compensation, repairs, taxes, interest, bad debts, depreciation, advertising, etc.)
  • Result equals taxable income before special deductions and NOL deduction
  • Subtract NOL deduction (§ 172, limited to 80% of taxable income for post-2017 NOLs)
  • Subtract special deductions (dividends received deduction under § 243)
  • Result equals taxable income subject to tax under § 11
• Taxable income before special deductions. Form 1120, Line 30 reports "Taxable income before special deductions." Special deductions reported on Schedule C include the DRD (§ 243), the § 250 deduction for FDII and GILTI, and the NOL deduction (§ 172). These are subtracted after the ordinary deductions on Lines 12 through 29.
• CAUTION. Do not apply the § 199A qualified business income deduction to C corporations. § 199(a) expressly provides that the deduction applies only in the case of a taxpayer other than a corporation. C corporations are statutorily excluded from this deduction. § 199(a). The IRS confirms that income earned through a C corporation is not eligible for the § 199A deduction.
• TRAP. The excess business loss limitation under § 461(l) does not apply to C corporations. The statute applies only to a taxpayer other than a corporation. § 461(l)(1). C corporation losses are instead governed solely by § 172 (NOL rules). A C corporation can generate an NOL in a given year subject only to the 80% of taxable income limitation for post-2017 NOLs.
• EXAMPLE. Corporation A has gross receipts of $2,000,000, COGS of $800,000, and deductions of $700,000. Taxable income before NOL and special deductions is $500,000. Corporation A has a post-2017 NOL carryover of $100,000. The NOL deduction is limited to 80% of $500,000 = $400,000, so the full $100,000 is deductible. Taxable income before the DRD is $400,000. If Corporation A received $50,000 of dividends from a less-than-20%-owned domestic corporation, the DRD is limited to 50% x $50,000 = $25,000 (subject to the § 246(b) taxable income limitation of 50% of modified taxable income). Final taxable income is $375,000, and the § 11 tax is $375,000 x 21% = $78,750.

Step 2. Gross Income Inclusions

"Except as otherwise provided in this subtitle, gross income means all income from whatever source derived, including (but not limited to) the following items." § 61(a).

• The all-income presumption. § 61(a) establishes that gross income is presumptively all-inclusive. The fifteen enumerated items in § 61(a)(1) through (15) are illustrative, not exhaustive. The Supreme Court defined income as undeniable accessions to wealth, clearly realized, and over which the taxpayers have complete dominion. Commissioner v. Glenshaw Glass Co., 348 U.S. 426 (1955). This broad definition means that any accession to wealth that is not expressly excluded by the Code must be included in gross income.
• Key corporate gross income items. A C corporation must include in gross income all of the following items:
  • Business receipts. Gross income derived from business under § 61(a)(2), including sales of inventory, services revenue, fees, and commissions. This is the primary income source for operating corporations
  • Dividends. § 61(a)(7) includes dividends in gross income. § 301(c)(1) provides that the portion of a corporate distribution constituting a dividend (as defined in § 316, to the extent of earnings and profits) shall be included in gross income. The dividends received deduction under § 243 is taken after inclusion as a special deduction, not as an exclusion from gross income
  • Interest. § 61(a)(4) includes interest in gross income. Tax-exempt interest under § 103 is excluded from gross income for regular tax purposes but is included for purposes of computing earnings and profits under § 312
  • Rents. § 61(a)(5) includes gross rents from real or personal property
  • Royalties. § 61(a)(6) includes royalties from the use of intangible property
  • Gains from dealings in property. § 61(a)(3) includes gains from the sale or other disposition of assets, including depreciable business property (subject to § 1231 netting), capital assets (subject to § 1211), and inventory (ordinary income)
  • Cancellation of indebtedness income. § 61(a)(12) includes income from discharge of indebtedness, subject to exceptions in § 108 for bankrupt and insolvent taxpayers
  • Tax refunds. State income tax refunds are includible to the extent the original deduction produced a tax benefit under § 111
  • Income from discharge of indebtedness. COD income is includible unless an exception applies. For C corporations, the § 108(a)(1)(A) and (B) exceptions apply to discharges in Title 11 cases and when the taxpayer is insolvent
• Timing of income recognition. Accrual-method corporations generally recognize income when all events have occurred that fix the right to receive the income and the amount can be determined with reasonable accuracy. § 451. This is the all-events test. Cash-method corporations recognize income when actually or constructively received. § 451. Most C corporations are required to use the accrual method under § 448(a), subject to exceptions for farming businesses, qualified personal service corporations, and small business taxpayers meeting the § 448(c) gross receipts test.
• TRAP. Illegal income is includible in gross income. James v. United States, 366 U.S. 213 (1961). A C corporation must report income from illegal activities even though the related expenses may be nondeductible under § 162(c) or § 162(f).

Step 3. Business Expense Deductions Under § 162

"There shall be allowed as a deduction all the ordinary and necessary expenses paid or incurred during the taxable year in carrying on any trade or business." § 162(a).

• The three-part deductibility test. Every § 162 deduction must satisfy three requirements, as articulated by the Supreme Court in Welch v. Helvering, 290 U.S. 111 (1933). The expense must be (1) ordinary (common and accepted in the particular business context), (2) necessary (appropriate and helpful for the development of the business, not strictly indispensable), and (3) paid or incurred in carrying on a trade or business. In Deputy v. du Pont, 308 U.S. 488 (1940), the Court clarified that ordinary means normal, usual, or customary in the context of the taxpayer's business, not necessarily habitual or recurring.
• Specific corporate deductions under § 162(a)(1) through (3). § 162(a) expressly authorizes deductions for three categories:
  • Compensation. A reasonable allowance for salaries or other compensation for personal services actually rendered. § 162(a)(1). Excessive compensation to shareholder-employees may be recharacterized as nondeductible dividends. The reasonableness standard considers the nature of the services, the corporation's financial condition, and comparable compensation for similar services
  • Business travel. Traveling expenses (including amounts expended for meals and lodging other than amounts which are lavish or extravagant) while away from home in the pursuit of a trade or business. § 162(a)(2)
  • Rent. Rentals or other payments required to be made as a condition to the continued use or possession of property. § 162(a)(3)
• § 162(b) charitable contribution exclusion. § 162(b) provides that no deduction shall be allowed under subsection (a) for any contribution or gift which would be allowable as a deduction under section 170 were it not for the percentage limitations, the dollar limitations, or the requirements as to the time of payment. Charitable contributions must be deducted under § 170, not § 162. This prevents taxpayers from bypassing the § 170 limitations by characterizing contributions as business expenses.
• Additional § 162 limitations for corporations.
  • § 162(c). No deduction for illegal bribes, kickbacks, or other illegal payments to government officials or other persons
  • § 162(f). No deduction for fines, penalties, or similar amounts paid to governments for violation of law
  • § 162(m). Deduction limitation on compensation over $1 million paid to covered employees. Post-TCJA amendments to § 162(m) expanded covered employees to include the CEO, CFO, and the three other highest-paid executive officers. The limitation applies to compensation for services during the taxable year, with exceptions for commissions and performance-based compensation removed by the TCJA
  • § 274(a). Entertainment expenses are nondeductible, regardless of business connection
  • § 274(n). Business meals generally limited to 50% deduction
  • § 274(a)(4). Employer-provided qualified transportation fringe benefits are nondeductible
• Capital expenditure distinction. Expenses that create or enhance a separate asset, produce benefits extending substantially beyond the taxable year, or adapt property to a new or different use must be capitalized under § 263(a), not deducted under § 162. In Indopco, Inc. v. Commissioner, 503 U.S. 79 (1992), the Supreme Court held that costs which produce significant future benefits must be capitalized, even if not connected to a specific identifiable asset. This includes investment banking fees for friendly acquisitions, environmental remediation costs that enhance property value, and costs of defending or perfecting title to property.
• TRAP. The 50% meals deduction limitation applies to C corporations. Under § 274(n)(1), the amount allowable as a deduction for food and beverages is generally limited to 50% of the amount otherwise deductible. There are exceptions for employer-provided meals at an eating facility and certain reimbursed employee expenses.

Step 4. Depreciation and Amortization

"There shall be allowed as a depreciation deduction a reasonable allowance for the exhaustion, wear and tear (including a reasonable allowance for obsolescence) of property used in the trade or business." § 167(a).

• § 168 MACRS depreciation system. Most tangible depreciable property placed in service after 1986 is depreciated under the Modified Accelerated Cost Recovery System. § 168. MACRS specifies recovery periods, depreciation methods, and conventions. Key property classes and their depreciation parameters include:
  • 3-year property (special tools, racehorses over 2 years old). 200% declining balance method. Half-year or mid-quarter convention. Year 1 rate 33.33%, Year 2 44.45%, Year 3 14.81%, Year 4 7.41%
  • 5-year property (computers, automobiles, office equipment, light trucks, appliances). 200% DB. Half-year or mid-quarter convention. Year 1 rate 20.00%, Year 2 32.00%, Year 3 19.20%, Year 4 11.52%, Year 5 11.52%, Year 6 5.76%
  • 7-year property (office furniture, fixtures, agricultural machinery, equipment not in other classes). 200% DB. Half-year or mid-quarter convention. Year 1 rate 14.29%, Year 2 24.49%, Year 3 17.49%, Year 4 12.49%, Year 5 8.93%, Year 6 8.92%, Year 7 8.93%, Year 8 4.46%
  • 10-year property (vessels, barges, single-purpose agricultural structures, trees/vines bearing fruits or nuts). 200% DB. Half-year or mid-quarter convention
  • 15-year property (land improvements, qualified improvement property, gas station convenience stores). 150% DB. Half-year or mid-quarter convention. Year 1 rate 5.00%, Year 2 9.50%, Year 3 8.55%
  • 20-year property (farm buildings, municipal sewers, qualified telecommunication property). 150% DB. Half-year or mid-quarter convention
  • Residential rental property (27.5 years). Straight-line method. Mid-month convention. Year 1 rate ranges from 0.152% (December placement) to 3.485% (January placement). Years 2 through 27 at 3.636%. Year 28 at 3.637%
  • Nonresidential real property (39 years). Straight-line method. Mid-month convention. Year 1 rate ranges from 0.107% (December placement) to 2.461% (January placement). Years 2 through 39 at 2.564%. Year 40 at 0.107%
• § 174 R&E expenditures. The One Big Beautiful Bill Act, enacted July 2025, fundamentally changed the treatment of research and experimental expenditures for tax years beginning after December 31, 2024:
  • Domestic R&E immediately deductible. § 174A(a) provides that a deduction is allowed for any domestic research or experimental expenditures paid or incurred during the taxable year. This reverses the TCJA mandatory amortization rule that required domestic R&E to be capitalized and amortized over 5 years
  • Foreign R&E still amortized. § 174 continues to require foreign research and experimental expenditures to be amortized ratably over 15 years. The amortization begins with the midpoint of the taxable year
  • Optional amortization election. § 174A(c) allows taxpayers to elect to capitalize domestic R&E and amortize over a period of not less than 60 months. The amortization period begins with the month in which the taxpayer first realizes benefits from the expenditures. The election is made by attaching a statement to the timely-filed return
  • Software development. § 174A(d)(3) provides that amounts paid or incurred in connection with software development are treated as research or experimental expenditures
  • Transitional rule. Taxpayers who capitalized domestic R&E under the TCJA rules for tax years beginning after December 31, 2021 and before January 1, 2025 may elect to either amortize the remaining unamortized amount in full in the first taxable year beginning after December 31, 2024, or amortize it over 2 taxable years. Small business taxpayers (average annual gross receipts not exceeding $31,000,000 for 2025) may elect to retroactively apply § 174A to those years
• Historical context on R&E treatment.
  • Pre-TCJA (before 2022). R&E expenditures were immediately deductible or could be amortized over not less than 60 months
  • TCJA (2022-2024). Domestic R&E was capitalized and amortized over 5 years using the midpoint convention. Foreign R&E was capitalized and amortized over 15 years
  • OBBBA (2025+). Domestic R&E is immediately deductible under § 174A (default). Foreign R&E remains capitalized and amortized over 15 years under § 174
• § 195 start-up costs. OBBBA § 70303 significantly enhanced the start-up expenditure deduction for businesses beginning operations in taxable years starting after December 31, 2024:
  • Immediate deduction of up to $50,000 (increased from $5,000)
  • Phase-out begins when start-up expenditures exceed $500,000 (increased from $50,000)
  • Full phase-out at $550,000 (when the $50,000 deduction is fully reduced to zero)
  • Remaining costs amortized over 180 months (15 years) beginning with the month the active trade or business begins
  • § 195(c)(1) defines start-up expenditures as amounts paid or incurred in connection with investigating the creation or acquisition of a trade or business, creating a trade or business, or any activity engaged in for profit before the day the active trade or business begins, in anticipation of the activity becoming an active trade or business, provided the expenditure would be allowable as a deduction if paid or incurred in connection with an existing active trade or business
• § 248 organizational expenditures. § 248 allows C corporations to elect to amortize organizational expenditures. Under § 248(a), the corporation may deduct up to $5,000 (this may be increased to $50,000 by OBBBA § 70303, but monitor official statutory updates as compilations may lag). The $5,000 is reduced (but not below zero) by the amount organizational expenditures exceed $50,000. The remainder is amortized over 180 months beginning with the month the corporation begins business. Treas. Reg. § 1.248-1 provides a deemed election for the taxable year in which the corporation begins business. To opt out, the corporation must affirmatively elect to capitalize. Qualifying organizational expenditures include legal services for drafting the charter and bylaws, accounting services, fees paid to the state of incorporation, and expenses of organizational meetings. Costs connected with issuing or selling stock or transferring assets to the corporation do not qualify.
• EXAMPLE. Corporation B pays $60,000 of start-up costs in 2025 before beginning business. Under OBBBA rules, the immediate deduction is $50,000 reduced by the excess of $60,000 over $500,000 (no reduction since $60,000 does not exceed $500,000). The full $50,000 is deductible immediately. The remaining $10,000 is amortized over 180 months at $55.56 per month, yielding a first-year deduction (assuming 12 months) of $667. Total first-year start-up deduction is $50,667.
• CAUTION. Pre-opening expenses that would be capital in nature even for an existing business (such as acquiring depreciable property) are not start-up expenditures under § 195. These must be capitalized into the basis of the asset and depreciated or amortized under the applicable provision.

Step 5. The § 179 Expense Election

"A taxpayer may elect to treat the cost of any section 179 property as an expense which is not chargeable to capital account." § 179(a).

• § 179(a) election mechanics. A taxpayer may elect to treat the cost of § 179 property as an expense not chargeable to capital account. Any cost so treated is allowed as a deduction for the taxable year in which the § 179 property is placed in service. § 179(a). The election is made on Form 4562, Part I. It must be filed with the original return (or on an amended return filed within the statutory period). The election is revocable only with IRS consent, though for the 2025 taxable year a revocation may be made by filing an amended return within the statutory period. The election applies in lieu of depreciating the property under MACRS.
• § 179(d)(1) definition of qualifying property. § 179 property means tangible personal property that is § 38 property (generally, most depreciable tangible personal property used in a trade or business) acquired by purchase for use in the active conduct of a trade or business. § 179(d)(1). Eligible property categories include:
  • Machinery and equipment
  • Office furniture and equipment
  • Computers and peripheral equipment
  • Business vehicles (subject to § 280F limitations)
  • Property contained in or attached to a building that is not a structural component (refrigerators, grocery counters, printing presses, testing equipment, signs)
  • Livestock including horses, cattle, hogs, sheep, goats, and fur-bearing animals
  • Portable air conditioners or heaters placed in service after 2015
  • Off-the-shelf computer software
  • Qualified improvement property (interior improvements to nonresidential real property, excluding enlargements, elevators/escalators, and internal structural framework)
  • Specified improvements to nonresidential real property placed in service after the building was first placed in service (roofs, HVAC, fire protection and alarm systems, security systems)
• Property that does NOT qualify for § 179. Land and land improvements, buildings and structural components (except qualified real property as noted above), property used predominantly outside the United States, property used by tax-exempt organizations, property held for investment, property used 50% or less for business, property acquired by gift or inheritance, property acquired from a related party, and inventory held for sale.
• § 179(b)(1) dollar limitation. For tax years beginning in 2025, the maximum § 179 deduction is $2,500,000 (increased from $1,220,000 for 2024 by OBBBA § 70301). For tax years beginning in 2026, the maximum deduction is $2,560,000 (indexed for inflation).
• § 179(b)(2) phase-out threshold. For tax years beginning in 2025, the § 179 deduction is reduced dollar-for-dollar when total qualifying property placed in service during the taxable year exceeds $4,000,000 (increased from $3,050,000 for 2024). Full phase-out occurs when total qualifying property placed in service equals or exceeds $6,500,000 ($2,500,000 + $4,000,000). For 2026, the threshold is $4,090,000 with full phase-out at $6,650,000.
• EXAMPLE. In 2025, Corporation C places in service $4,500,000 of § 179 qualifying property. The excess over the phase-out threshold is $4,500,000 - $4,000,000 = $500,000. The maximum § 179 deduction is reduced to $2,500,000 - $500,000 = $2,000,000.
• § 179(b)(3) taxable income limitation. The § 179 deduction (after applying the dollar limitation and phase-out) cannot exceed the aggregate taxable income of the taxpayer for the taxable year derived from the active conduct of any trade or business. § 179(b)(3)(A). Taxable income for this purpose is computed without regard to the § 179 deduction itself, NOL carryovers, and certain other items. Treas. Reg. § 1.179-2(c). The § 179 deduction cannot create or increase an NOL.
• § 179(b)(4) carryforward. Any amount elected to be expensed under § 179 that is disallowed solely by reason of the taxable income limitation is carried forward indefinitely to succeeding taxable years. The carryforward amount is subject to the same dollar limit and taxable income limitation in the carryforward year.
• § 179(d)(10) recapture on business use dropping to 50% or below. If § 179 property is not used predominantly (more than 50%) in the taxpayer's trade or business at any time before the end of the property's recovery period, the taxpayer must recapture the benefit of the § 179 deduction. The recapture amount equals the § 179 deduction taken minus the depreciation that would have been allowable on that amount using regular MACRS through the recapture year. The recaptured amount is ordinary income. Treas. Reg. § 1.179-1(e). The property's basis is increased by the recapture amount.
• § 280F luxury automobile limits for corporate vehicles. § 280F imposes dollar caps on depreciation (including § 179 expense and bonus depreciation) for passenger automobiles. A passenger automobile is any 4-wheeled vehicle manufactured primarily for use on public streets with an unloaded gross vehicle weight of 6,000 pounds or less. § 280F(d)(5). For trucks and vans, the threshold is based on gross vehicle weight rating rather than unloaded weight. For vehicles placed in service in 2025, the depreciation caps are $12,200 Year 1 without bonus, $20,200 Year 1 with bonus, $19,600 Year 2, $11,800 Year 3, and $7,060 Year 4 and later.
• SUV limitation. For sport utility vehicles with GVWR over 6,000 pounds but not more than 14,000 pounds, the § 179 deduction is capped at $31,300 for 2025. Vehicles over 6,000 pounds GVWR are not subject to § 280F depreciation caps and are eligible for full § 179 and bonus depreciation.
• § 168(k) bonus depreciation. OBBBA § 70301 permanently reinstated 100% bonus depreciation for property acquired and placed in service after January 19, 2025. For property placed in service between January 1, 2025 and January 19, 2025, the TCJA phase-down rate of 40% applies (60% for long-production-period property and aircraft). Taxpayers may elect to take 40% (or 60% for LPP/aircraft) instead of 100% for qualifying property placed in service during their first taxable year ending after January 19, 2025. Qualifying property includes property with a recovery period of 20 years or less, depreciable computer software, qualified improvement property, and certain used property meeting requirements.
• TRAP. The § 179 deduction is applied before bonus depreciation. If both are claimed, § 179 reduces basis first, and bonus depreciation is computed on the remaining basis. The sum of § 179 expense plus bonus depreciation plus regular MACRS depreciation cannot exceed the § 280F limits for passenger automobiles.
• CAUTION. Bonus depreciation can create or increase an NOL because it is not limited by taxable income. This is a key difference from the § 179 deduction. If a corporation has sufficient basis in qualifying property, it can claim 100% bonus depreciation and generate an NOL that can be carried forward indefinitely (subject to the 80% limitation in future years).

Step 6. Depreciation Recapture under § 1245 and § 1250

"Upon a disposition of section 1245 property, the amount by which the lower of (A) the recomputed basis of the property, or (B) the amount realized, exceeds the adjusted basis of the property shall be treated as ordinary income." § 1245(a)(1).

"If section 1250 property is disposed of, the amount by which the additional depreciation in respect of the property is treated as gain which is ordinary income." § 1250(a)(1)(A).

• § 1245 recapture for personal property. § 1245 applies to depreciable personal property. Upon disposition, gain is treated as ordinary income to the extent of all depreciation allowed or allowable on the property. § 1245(a)(1). This includes ordinary MACRS depreciation, bonus depreciation, and § 179 expense deductions. § 1245 recapture equals the lesser of gain realized or total depreciation taken. Any gain remaining after § 1245 recapture is § 1231 gain (if the property was used in the trade or business and held for more than one year). § 1245 property includes tangible personal property, single-purpose agricultural structures, storage facilities for petroleum products, and certain real property that has been treated as § 1245 property by election or change of use.
• § 1250 recapture for real property. § 1250 applies to depreciable real property (other than property that is § 1245 property). Gain is ordinary income to the extent of additional depreciation, defined as the excess of actual depreciation adjustments over the adjustments that would have resulted if the straight-line method had been used. § 1250(b)(1). For property held more than one year, the applicable percentage is 100% minus 1% for each full month the property was held over 100 full months. For most post-1986 MACRS real property, additional depreciation is zero because straight-line depreciation is mandatory, meaning § 1250 recapture is typically zero.
• The § 1231 netting process. After applying § 1245 and § 1250 recapture, any remaining gain on business property held more than one year is § 1231 gain. § 1231(a). If § 1231 gains exceed § 1231 losses for the year, the net gain is treated as long-term capital gain. If § 1231 losses exceed gains, the net loss is treated as ordinary loss (fully deductible). § 1231(b). The five-year lookback rule in § 1231(c) requires that current-year net § 1231 gain be treated as ordinary income to the extent of nonrecaptured § 1231 losses from the preceding five years.
• Corporate capital loss treatment. No deduction against ordinary income. § 1211(a) provides that for a corporation, losses from sales or exchanges of capital assets shall be allowed only to the extent of gains from such sales or exchanges. C corporations may NOT deduct any net capital losses against ordinary income. This is a critical difference from individuals who may deduct up to $3,000 of net capital losses against ordinary income. § 1211(b).
• § 1212(a)(1) carryback and carryforward. Excess corporate capital losses are carried back 3 years and forward 5 years (for pre-2018 losses). The TCJA eliminated the 3-year carryback for tax years beginning after December 31, 2017. The CARES Act temporarily restored the 3-year carryback for 2018-2020 losses. Current law (post-CARES Act) generally provides only a 5-year carryforward for tax years beginning after December 31, 2017. Ordering rules apply. Short-term losses are carried first, then long-term losses, to the earliest year in the carryback/carryforward period.
• CAUTION. Corporate capital losses receive no preferential treatment. A C corporation with $100,000 of capital losses and $100,000 of ordinary income can deduct zero capital losses against ordinary income. The $100,000 of capital losses must be carried back or forward to offset capital gains. Unlike individuals, corporations have no $3,000 safety valve.
• TRAP. When a C corporation sells § 1231 property at a gain, the § 1245 or § 1250 recapture portion is ordinary income, and the remaining gain is § 1231 gain (treated as long-term capital gain if net § 1231 is positive). However, since corporations have no preferential capital gains rate (all income is taxed at 21%), the character distinction matters primarily for the capital loss limitation, the DRD taxable income computation, and E&P calculations.

Step 7. § 291 Special Corporate Adjustments

"In the case of section 1250 property which is disposed of during the taxable year, 20 percent of the excess (if any) of -- (A) the amount which would be treated as ordinary income if such property was section 1245 property, over (B) the amount treated as ordinary income under section 1250 (determined without regard to this paragraph), shall be treated as gain which is ordinary income under section 1250 and shall be recognized notwithstanding any other provision of this title." § 291(a)(1).

• § 291(a)(1) 20% additional recapture for C corporations. § 291(a)(1) applies exclusively to C corporations (not individuals, partnerships, S corporations, trusts, or estates). It recaptures a portion of what would otherwise be capital gain on the sale of § 1250 property as ordinary income. The provision was enacted by TEFRA § 204(a) and applies to dispositions after December 31, 1982, in taxable years ending after such date. The critical phrase shall be recognized notwithstanding any other provision of this title means § 291 recapture applies even in otherwise non-recognition transactions to the extent boot is received.
• Step-by-step § 291(a)(1) computation.
  1. Compute total realized gain (amount realized minus adjusted basis)
  2. Compute hypothetical § 1245 recapture (all depreciation taken on the property, limited to realized gain)
  3. Compute actual § 1250 recapture (additional depreciation, which is the excess of actual depreciation over straight-line depreciation, limited to realized gain)
  4. Compute the excess, which equals hypothetical § 1245 recapture minus actual § 1250 recapture
  5. Multiply the excess by 20%. This is the § 291(a)(1) additional ordinary income.
• For straight-line MACRS property (post-1986). Since MACRS requires straight-line depreciation for all real property (27.5 years for residential rental, 39 years for nonresidential real), there is no additional depreciation and § 1250 recapture is zero. Therefore the formula simplifies. § 291(a)(1) recapture equals 20% of total depreciation taken (limited to realized gain). The remaining 80% of the depreciation-related gain is treated as § 1231 gain.
• Remaining gain character after § 291. After applying § 1250 recapture (if any) and § 291(a)(1) recapture, the remaining gain is allocated between the unrecaptured § 1250 gain portion (remaining depreciation-related gain) and the true economic gain (gain above original cost). For a C corporation, all remaining gain is ultimately taxed at the flat 21% rate because corporations have no preferential capital gains rate. However, the character distinction matters for NOL computations, the DRD taxable income limitation, E&P calculations, and state tax purposes.
• § 291(a)(2) 20% reduction in percentage depletion for iron ore and coal. § 291(a)(2) reduces the percentage depletion deduction available to C corporations mining iron ore and coal (including lignite) by 20% of the excess of the § 613 deduction over the adjusted basis of the property. This provision is effective for taxable years beginning after December 31, 1983. Independent oil and gas producers are not subject to § 291(a)(2) because their percentage depletion is governed by § 613A rather than § 613.
• § 291(a)(3) financial institution preference items. § 291(a)(3) reduces deductions for financial institution preference items by 20%. The only currently operative preference item is interest on indebtedness incurred to purchase or carry tax-exempt obligations acquired after December 31, 1982 and before August 8, 1986. For obligations acquired after August 7, 1986, § 265(b) applies a 100% disallowance instead, rendering § 291(a)(3) inapplicable.
• § 291(a)(4) amortization of pollution control facilities. If a C corporation makes a § 169 election for a certified pollution control facility, the amortizable basis is reduced by 20%. The disallowed 20% of basis is still eligible for regular depreciation under § 168. § 291(c)(1).
• § 291(c) pollution control facility exemption from § 291(a)(1). § 291(c)(2) provides that § 291(a)(1) does not apply to any § 1250 property that is part of a certified pollution control facility with respect to which a § 169 election was made. This is a complete exemption from the 20% additional recapture for qualifying pollution control property.
• § 291(b) integrated oil company IDCs and exploration costs. § 291(b) requires integrated oil companies to reduce immediate deductions for intangible drilling costs under § 263(c), mine development costs under § 616(a), and mine exploration costs under § 617(a) by 30%. The disallowed 30% is amortized ratably over 60 months beginning with the month the costs are paid or incurred. Non-integrated oil companies (independent producers) are not subject to § 291(b).
• EXAMPLE. Corporation D (a C corporation) sells a commercial office building (post-1986 MACRS, 39-year straight-line) for $1,300,000. The building was purchased for $1,000,000 (excluding land). Total straight-line depreciation taken is $200,000. Adjusted basis is $800,000. Total realized gain is $500,000. § 1250 recapture is $0 because straight-line depreciation produces no additional depreciation. Hypothetical § 1245 recapture (total depreciation taken, limited to gain) is $200,000. § 291(a)(1) additional ordinary income is 20% x ($200,000 - $0) = $40,000. The remaining $460,000 of gain is § 1231 gain ($200,000 - $40,000 = $160,000 from depreciation-related gain plus $300,000 of true economic gain above original cost). The $40,000 of § 291 recapture is ordinary income. The $460,000 of § 1231 gain is treated as long-term capital gain (assuming net § 1231 is positive) and taxed at 21%.
• Reporting mechanics. § 291(a)(1) recapture is computed and reported on Form 4797, Part III, Line 26f. The IRS Form 4797 instructions state that "The amount the corporation treats as ordinary income under section 291 is 20% of the excess, if any, of the amount that would be treated as ordinary income if such property were section 1245 property, over the amount treated as ordinary income under section 1250. If the corporation used the straight line method of depreciation, the ordinary income under section 291 is 20% of the amount figured under section 1245."
• State conformity note. States that conform to federal MACRS generally also conform to § 291 for C corporations. However, states that do not conform to federal bonus depreciation (such as California) or that have independent depreciation systems will require separate recapture computations using state-specific basis and depreciation amounts. Maintain separate depreciation schedules for each non-conforming state.

Step 8. Dividends Received Deduction

"In the case of a corporation, there shall be allowed as a deduction an amount equal to the following percentages of the amount received as dividends from a domestic corporation which is subject to taxation under this chapter: (1) 50 percent, in the case of dividends other than dividends described in paragraph (2) or (3); (2) 100 percent, in the case of dividends received by a small business investment company; and (3) 100 percent, in the case of qualifying dividends (as defined in subsection (b)(1))." § 243(a).

• The tiered DRD structure. § 243(a) provides three tiers of deduction for dividends received by a C corporation from domestic corporations subject to taxation under chapter 1:
  • 50% DRD. For dividends from domestic corporations in which the recipient owns less than 20% (by vote and value). § 243(a)(1). The rate was reduced from 70% to 50% by the TCJA for tax years beginning after December 31, 2017
  • 65% DRD. For dividends from 20-percent owned corporations in which the recipient owns 20% or more (by vote and value). § 243(c)(1) substitutes 65 percent for 50 percent in § 243(a)(1). The rate was reduced from 80% to 65% effective for tax years beginning after December 31, 2017
  • 100% DRD for SBICs. Dividends received by small business investment companies operating under the Small Business Investment Act of 1958 (15 U.S.C. 661 and following). § 243(a)(2)
  • 100% DRD for affiliated group members. Qualifying dividends from members of the same affiliated group where the parent owns 80% or more of the vote and value. § 243(a)(3) and § 243(b)
• § 243(c) 20-percent owned corporation definition. A 20-percent owned corporation means any corporation if 20% or more of the stock (by vote and by value) is owned by the taxpayer. § 1504(a)(4) nonvoting preferred stock is excluded from the ownership calculation. Treas. Reg. § 1.243-4. To qualify for the 65% DRD, the 20% ownership must exist on the date the dividend is received.
• § 243(b) qualifying dividends from affiliated group members. A qualifying dividend means any dividend received by a corporation that is a member of the same affiliated group as the distributing corporation on the date the dividend is received. The dividend must be distributed out of earnings and profits of a taxable year ending after December 31, 1963, during which the distributing and receiving corporations were members of the same affiliated group on each day. § 243(b)(1). Affiliated group has the meaning given by § 1504(a). § 1504(b)(2) and (c) do not apply. § 243(b)(3). All members must have consistent foreign tax treatment. § 243(b)(4).
• § 246(c) holding period requirement. No DRD is allowed for any dividend on stock held by the taxpayer for 45 days or less during the 91-day period beginning 45 days before the ex-dividend date. § 246(c)(1)(A). For preferred stock dividends attributable to periods exceeding 366 days, the requirement extends to more than 90 days during a 181-day period beginning 90 days before the ex-dividend date. § 246(c)(2). The holding period is reduced for periods where the taxpayer has diminished risk of loss by reason of certain hedging positions, short sales, or options. § 246(c)(4).
• § 246(c)(5) holding period for § 245A dividends. For dividends eligible for the § 245A deduction (foreign-source portion from specified 10-percent owned foreign corporations), the stock must be held for more than 365 days during the 731-day period beginning on the date which is 365 days before the date on which the share becomes ex-dividend. § 246(c)(5).
• § 246A reduction for debt-financed portfolio stock. § 246A reduces the DRD for dividends on debt-financed portfolio stock by substituting a percentage equal to the base DRD percentage (50% or 65%) multiplied by 100% minus the average indebtedness percentage. § 246A(a)(1). The average indebtedness percentage is the ratio of the average amount of indebtedness incurred or continued to purchase or carry the portfolio stock to the average amount of the taxpayer's basis in the stock. § 246A(d). This provision does not apply to qualifying dividends eligible for the 100% DRD or to dividends received by SBICs. § 246A(b). Debt-financed portfolio stock means any stock if at some time during the taxable year there is an indebtedness incurred or continued to purchase or carry the stock. § 246A(d)(1).
• § 245A 100% DRD for foreign-source dividends. § 245A(a) provides a 100% deduction for the foreign-source portion of any dividend received by a domestic corporation that is a United States shareholder with respect to a specified 10-percent owned foreign corporation. A specified 10-percent owned foreign corporation means any foreign corporation with respect to which any domestic corporation is a United States shareholder (meaning 10% or more of the total combined voting power or value), excluding PFICs that are not CFCs. § 245A(b). The foreign-source portion of any dividend is the amount which bears the same ratio to the dividend as (1) the undistributed foreign earnings of the corporation, bears to (2) the total undistributed earnings of the corporation. § 245A(c). No foreign tax credit or deduction is allowed with respect to amounts qualifying for the § 245A deduction. § 245A(d).
• § 246(b) taxable income limitation. The aggregate DRD under § 243(a)(1) (the 50% and 65% tiers), §§ 245(a) and (b), and the § 250 deduction is limited to the applicable percentage of taxable income computed without regard to the DRD itself, the § 250 deduction, the § 172 NOL deduction, § 199A, § 1059 adjustments, and capital loss carrybacks. § 246(b)(1). The limitation is applied in two steps:
  • First, 65% of modified taxable income for the 65% tier dividends and § 250 deduction. § 246(b)(3)(A)
  • Second, 50% of further reduced taxable income for the 50% tier dividends and remaining § 250 deduction. § 246(b)(3)(B)
• § 246(b)(2) NOL exception. Full DRD allowed even if it creates or increases NOL. The taxable income limitation in § 246(b)(1) shall not apply for any taxable year for which there is a net operating loss. If the corporation has an NOL before the DRD, the full DRD is allowed without the § 246(b) limitation. § 246(b)(2). The term net operating loss means a deficit in taxable income, computed with the modifications to § 172. Treas. Reg. § 1.246-2.
• § 1059 extraordinary dividends basis reduction. If a corporation receives an extraordinary dividend with respect to stock held for 2 years or less, the corporation must reduce its basis in the stock by the nontaxed portion of the dividend. § 1059(a). An extraordinary dividend generally means any dividend equal to or in excess of 10% of the corporation's adjusted basis in the stock (5% for preferred stock). § 1059(c). All dividends with ex-dividend dates within an 85-consecutive-day period are treated as one dividend. § 1059(c)(3)(A). If the nontaxed portion exceeds the corporation's basis in the stock, the excess is treated as gain from sale or exchange. § 1059(a)(2). The nontaxed portion equals the total dividend received minus the tax on the dividend (or in the case of a DRD, the portion not deductible).
• The DRD ordering rule. Dividends are first included in gross income under § 301(c)(1) (to the extent of the distributing corporation's earnings and profits under § 316), and then the DRD is applied as a special deduction. The DRD is not an exclusion from gross income. This ordering matters for all percentage-of-income limitations (§ 163(j) ATI, § 246(b), § 170(b)(2)).
• Consolidated group dividends. Dividends distributed between members of an affiliated group filing a consolidated return are eliminated under § 243(b) (100% DRD). The consolidated return regulations provide that intercompany dividends are generally eliminated from the consolidated taxable income computation. Treas. Reg. § 1.1502-13.
• EXAMPLE. Corporation E (a C corporation) receives $100,000 of dividends from Corporation F (less than 20% owned, domestic). Corporation E also has other taxable income of $200,000. Before the DRD, taxable income is $300,000. The DRD is $100,000 x 50% = $50,000. Under § 246(b)(1), the DRD is limited to 50% of modified taxable income. Modified taxable income is computed without the DRD and § 172, which equals $300,000. The § 246(b) limitation is 50% x $300,000 = $150,000. Since the DRD of $50,000 is less than $150,000, the full $50,000 is allowed. Final taxable income is $250,000. If taxable income before the DRD had been $80,000 (creating an NOL after the DRD), § 246(b)(2) would apply and the full $50,000 DRD would be allowed even though it creates an NOL.
• TRAP. The 100% DRD for qualifying dividends under § 243(a)(3) (affiliated group dividends) and § 245A dividends (foreign-source dividends) are NOT subject to the § 246(b) taxable income limitation. The limitation in § 246(b)(1) applies only to § 243(a)(1) (the 50% and 65% tiers), §§ 245(a) and (b) (pre-TCJA foreign-source dividends), and § 250. 100% DRD dividends are always fully deductible.
• CAUTION. The § 245A holding period requirement (more than 365 days during a 731-day period) is significantly longer than the § 246(c)(1) holding period for domestic corporation dividends (more than 45 days during a 91-day period). A domestic corporation claiming the § 245A deduction must ensure it satisfies both the § 245A ownership test (10% or more of the foreign corporation) and the extended holding period.

Step 9. Net Operating Loss Deduction

"In the case of a taxable year beginning after December 31, 2020, [the NOL deduction shall not exceed] the sum of -- (A) the aggregate amount of net operating losses arising in taxable years beginning before January 1, 2018, carried to such taxable year, plus (B) the lesser of -- (i) the aggregate amount of net operating losses arising in taxable years beginning after December 31, 2017, carried to such taxable year, or (ii) 80 percent of the excess (if any) of -- (I) taxable income computed without regard to the deductions under this section and sections 199A and 250, over (II) the amount determined under subparagraph (A)." § 172(a)(2).

• § 172(a)(2) 80% taxable income limitation for post-2017 NOLs. For taxable years beginning after December 31, 2020, the NOL deduction is subject to an 80% of taxable income limitation for NOLs arising in taxable years beginning after December 31, 2017. The computation proceeds in two steps. First, deduct pre-2018 NOLs without limitation (subject to 20-year carryforward). Second, deduct post-2017 NOLs up to the lesser of (i) the available carryover or (ii) 80% of taxable income remaining after pre-2018 NOLs. Taxable income for the 80% computation is computed without regard to the § 172 (NOL) deduction, § 199A (QBI), and § 250 (FDII/GILTI) deductions. § 172(a)(2)(B)(ii)(I).
• Pre-2018 NOLs carry no 80% limitation and apply first. NOLs arising in tax years beginning before January 1, 2018 may offset taxable income on a dollar-for-dollar basis, subject only to the 20-year carryforward limitation. Pre-2018 NOLs are applied before post-2017 NOLs. Treas. Reg. § 1.172-4(a).
• § 172(b)(1) no carryback for post-2017 NOLs (except farming and insurance). Post-2017 NOLs generally may not be carried back. § 172(b)(1)(A)(ii). Two exceptions remain. (1) Farming losses under § 172(b)(1)(B) retain a 2-year carryback and 20-year carryforward (though the 80% limitation still applies to farming NOLs in carryforward years), and (2) nonlife insurance companies under § 172(b)(1)(C) retain a 2-year carryback and 20-year carryforward.
• § 172(b)(1)(A)(ii)(II) indefinite carryforward for post-2017 NOLs. Post-2017 NOLs may be carried forward to each taxable year following the taxable year of the loss indefinitely. There is no expiration for post-2017 NOL carryforwards. This replaces the prior 20-year carryforward period that applied to pre-2018 NOLs.
• CARES Act temporary modifications (expired). The CARES Act provided a 5-year carryback for NOLs arising in 2018, 2019, and 2020, and temporarily suspended the 80% limitation for those years. These provisions have fully sunset and do not apply to current years. For tax years beginning after December 31, 2020, the TCJA rules are fully operative.
• § 172(b)(3) election to waive carryback. Any taxpayer entitled to a carryback may elect to relinquish the entire carryback period with respect to a net operating loss for any taxable year. The election must be made by the due date (including extensions) for filing the return for the taxable year of the NOL. The election is irrevocable. In Apache Corp. v. Commissioner, 165 T.C. No. 11 (2025), the Tax Court held that the election relinquishes only the carryback period for the specific portion of the NOL to which it applies, not for all NOLs.
• § 382 limitation after ownership change. If an ownership change occurs (generally, a greater than 50 percentage point increase in ownership by 5% shareholders during a 3-year testing period), the amount of taxable income that may be offset by pre-change losses is limited to the § 382 limitation. The § 382 limitation equals the value of the old loss corporation on the change date multiplied by the long-term tax-exempt rate published monthly by the IRS. § 382(b)(1). The continuity of business requirement provides that if the new loss corporation does not continue the loss corporation's business enterprise for at least 2 years after the ownership change, the limitation is zero. § 382(c)(1). Recognized built-in gains increase the limitation dollar for dollar. Recognized built-in losses are treated as pre-change losses. § 382(h)(1) and § 382(h)(2).
• § 383 credit limitation. § 383 applies the principles of § 382 to limit the use of general business credits and minimum tax credits after an ownership change. The same value-based limitation applies to credit carryovers.
• § 384 built-in gain limitation. If a corporation acquires control of another corporation or acquires assets of another corporation in a reorganization and either corporation is a gain corporation (with net unrealized built-in gain exceeding the threshold amount), income attributable to recognized built-in gains during the 5-year recognition period may not be offset by pre-acquisition losses of the acquiring corporation (other than the gain corporation's own losses). § 384(a). This prevents trafficking in loss corporations through asset acquisitions.
• EXAMPLE. Corporation G has the following for 2025.
  • Taxable income before NOL is $500,000
  • Pre-2018 NOL carryover of $100,000 (fully usable, no limitation)
  • Post-2017 NOL carryover of $300,000
  • Taxable income after pre-2018 NOL is $400,000 ($500,000 - $100,000)
  • 80% limitation for post-2017 NOL equals 80% x $400,000 = $320,000
  • Post-2017 NOL deduction allowed is the lesser of $300,000 or $320,000, which equals $300,000
  • Total NOL deduction of $400,000 ($100,000 + $300,000)
  • Taxable income is $100,000
  • § 11 tax of $100,000 x 21% equals $21,000
• State NOL conformity issues. States vary significantly in their conformity to federal NOL rules. Many states decouple from the 80% limitation, allowing 100% offset of state taxable income. Most states do not allow carrybacks. California uses fixed-date conformity and does not automatically adopt federal changes. Some states (such as New York) have their own NOL computation and carryforward rules. Practitioners must maintain separate NOL schedules for federal and each state jurisdiction.

Step 10. Charitable Contribution Deductions

"In the case of a corporation -- (A) In general. The total deductions under subsection (a) for any taxable year (other than for contributions to which subparagraph (B) or (C) applies) shall not exceed 10 percent of the taxpayer's taxable income." § 170(b)(2).

• § 170(b)(2) 10% of taxable income limitation. A C corporation's charitable contribution deduction is limited to 10% of taxable income. Taxable income for this purpose is computed without regard to (i) § 170 itself, (ii) Part VIII of subchapter B (including the DRD under § 243, the § 250 deduction, and the § 245A deduction), (iii) any NOL carryback to the taxable year under § 172, (iv) § 249 (amortizable bond premium on convertible bonds), and (v) § 936 (Puerto Rico and possession tax credit). § 170(b)(2)(D). Taxable income DOES take into account NOL carryovers to the year (not carrybacks), regular business deductions, and depreciation.
• OBBBA 1% floor (effective 2026). For tax years beginning after December 31, 2025, OBBBA adds a 1% floor to the § 170(b)(2) limitation. A corporation may deduct charitable contributions only to the extent the aggregate contributions exceed 1% of taxable income, and the total deduction may not exceed 10% of taxable income. If charitable contributions equal or fall below 1% of taxable income, no deduction is allowed. This floor does not apply to contributions described in § 170(e)(3) (inventory) or § 170(e)(4) (scientific property).
• § 170(b)(2)(A) 5-year carryforward. Excess contributions that exceed the 10% limitation may be carried forward to each of the 5 succeeding taxable years. No carryback is permitted. Carryforwards are applied on a FIFO basis, with current-year contributions deducted first before carryover amounts. § 170(d)(2)(B).
• EXAMPLE. Corporation H has taxable income (computed under § 170(b)(2)(D)) of $1,000,000 and makes charitable contributions of $200,000. The § 170(b)(2) limitation is 10% x $1,000,000 = $100,000. Current-year deduction is $100,000. Excess of $100,000 is carried forward to each of the next 5 years. If taxable income in Year 2 is $500,000, the Year 2 limitation is $50,000. Year 2 contributions of $40,000 are deducted first, then $10,000 of Year 1 carryforward, leaving $90,000 of Year 1 carryforward for Years 3 through 6.
• § 170(e)(1) reduction for ordinary income property. The amount of any charitable contribution of property is reduced by the amount of gain that would not have been long-term capital gain if the property had been sold by the taxpayer at its fair market value. § 170(e)(1)(A). This generally limits deductions for ordinary income property (including inventory and depreciable property subject to § 1245 recapture) and short-term capital gain property to adjusted basis. Long-term capital gain property may generally be deducted at fair market value (subject to limitations for certain tangible personal property unrelated to the donee's exempt purpose and contributions to certain private foundations).
• § 170(e)(3) enhanced deduction for inventory donations. C corporations may claim an enhanced deduction for qualified contributions of inventory to qualifying charitable organizations. The deduction equals basis plus one-half of the unrealized appreciation (FMV minus basis), capped at twice the property's basis. § 170(e)(3)(B). The enhanced deduction applies only if the donee uses the property solely for the care of the ill, the needy, or infants, the property is not transferred by the donee in exchange for money or property, the taxpayer receives a written statement from the donee, and the basis is determined under § 263A. Food inventory contributions are subject to a separate 15% of taxable income limitation under § 170(e)(3)(C) (25% for contributions made in taxable years beginning after December 31, 2024 under the Food Donation Improvement Act).
• § 170(e)(4) scientific property donations. § 170(e)(4) provides a parallel enhanced deduction for contributions of qualified research property (tangible personal property used for research and experimental purposes) to qualifying educational or scientific organizations. The computation formula is identical to § 170(e)(3). Basis plus half the appreciation, capped at twice basis.
• § 170(h) conservation contributions. Qualified conservation contributions (contributions of qualified real property interests exclusively for conservation purposes) are subject to the general 10% limitation for C corporations. Corporate farmers and ranchers may deduct conservation contributions to the extent of taxable income reduced by other charitable contributions, with a 15-year carryover under § 170(f)(14).
• TRAP. Charitable contributions that qualify under § 170 may NOT be deducted as business expenses under § 162. § 162(b) expressly excludes contributions that would be deductible under § 170 but for percentage or dollar limitations. A corporation cannot bypass the § 170 limitations by characterizing a donation as an ordinary and necessary business expense.
• CAUTION. The 10% limitation is computed on taxable income without regard to the DRD and § 250 deductions. This means a corporation with large dividend income and the associated DRD may have a lower § 170 limitation than a corporation with equivalent taxable income from business operations.

Step 11. Business Interest Expense Limitation

"The amount allowed as a deduction under this chapter for business interest expense of any taxpayer for any taxable year shall not exceed the sum of -- (A) the business interest income of such taxpayer for such taxable year, (B) 30 percent of the adjusted taxable income of such taxpayer for such taxable year, and (C) the floor plan financing interest expense of such taxpayer for such taxable year." § 163(j)(1).

• § 163(j)(1) 30% of ATI limitation. § 163(j) limits the deduction for business interest expense to the sum of business interest income plus 30% of adjusted taxable income plus floor plan financing interest expense. § 163(j)(1). Excess business interest expense (the amount by which business interest expense exceeds the § 163(j)(1) limitation) is carried forward indefinitely and treated as business interest expense in the succeeding taxable year. § 163(j)(2).
• Adjusted taxable income (ATI) computation. ATI equals taxable income computed without regard to several items. These are items not allocable to a trade or business, business interest expense or income, the § 250 deduction, the § 199A deduction, and (for tax years beginning after December 31, 2024, per OBBBA) depreciation, amortization, and depletion. OBBBA restored the EBITDA-based ATI computation beginning in 2025, adding back depreciation and amortization. For tax years 2022 through 2024, ATI was computed without the D&A addback (EBIT-based). OBBBA also excludes CFC income inclusions under §§ 951(a), 951A(a), and § 78 from ATI for tax years beginning after December 31, 2025.
• § 163(j)(3) small business exception. § 163(j) does not apply to taxpayers (other than tax shelters as defined in § 448(d)(3)) meeting the § 448(c) gross receipts test. The threshold is $25,000,000 base amount, indexed for inflation. For 2025, the threshold is $31,000,000. Rev. Proc. 2024-40, § 3.31. The gross receipts test is applied by aggregating gross receipts of all persons treated as a single employer under § 52(a), (b), or § 414(m) or (o).
• Electing real property trades or businesses and farming businesses. Certain trades or businesses may elect out of § 163(j), but the trade-off is mandatory use of the Alternative Depreciation System with longer recovery periods and no bonus depreciation. § 163(j)(7). An electing real property trade or business is any trade or business described in § 469(c)(7)(C) (rental real estate activities in which the taxpayer materially participates). A farming business may also elect out.
• Application to C corporations versus partnerships. For C corporations, § 163(j) applies at the corporate level. For consolidated groups, a single limitation is applied at the consolidated return level. Treas. Reg. § 1.163(j)-4(d). For partnerships, § 163(j) applies at the partnership level, and any excess business interest is allocated to partners and may be deducted by a partner in a future year to the extent the partnership allocates excess taxable income or excess business interest income to that partner. § 163(j)(4).
• TRAP. § 163(j) can create a permanent disallowance if ATI remains insufficient to absorb the carried-forward interest in future years. Unlike NOLs that can eventually be used (subject to the 80% limitation), excess business interest carried forward under § 163(j)(2) remains subject to the limitation test in each subsequent year. If ATI is consistently low relative to interest expense, the carryforward can accumulate indefinitely without ever being deducted.
• CAUTION. The EBITDA-based ATI computation (with depreciation and amortization added back) for 2025+ means most corporations will have higher ATI and thus a higher § 163(j) limitation than under the EBIT-based computation that applied for 2022 through 2024. However, the concurrent removal of CFC income inclusions from ATI for 2026+ may reduce the limitation for multinational corporations with significant Subpart F or GILTI income inclusions.

Step 12. § 448 Cash Method Limitations

"Except as otherwise provided in this section, in the case of a -- (1) C corporation, (2) partnership which has a C corporation as a partner, or (3) tax shelter, taxable income shall not be computed under the cash receipts and disbursements method of accounting." § 448(a).

• § 448(a) general prohibition on cash method for C corporations. § 448(a) prohibits three categories of taxpayers from using the cash receipts and disbursements method of accounting. These are (1) C corporations, (2) partnerships with a C corporation as a partner, and (3) tax shelters. A partnership is prohibited from using the cash method if ANY partner is a C corporation, regardless of the C corporation's ownership percentage. This prevents circumvention of § 448(a)(1) by operating in partnership form.
• § 448(b) exceptions. Three independent exceptions allow otherwise prohibited taxpayers to use the cash method:
  • § 448(b)(1) farming business. Paragraphs (1) and (2) of subsection (a) do not apply to any farming business. A C corporation engaged in farming may use the cash method without regard to the general prohibition. Farming business is defined in § 263A(e)(4) to include the trade or business of the operation of a nursery or sod farm, the raising or harvesting of trees bearing fruit, nuts, or other crops, or ornamental trees, and certain contract growing arrangements
  • § 448(b)(2) qualified personal service corporation. Paragraphs (1) and (2) of subsection (a) do not apply to a qualified personal service corporation. A QPSC is treated as an individual for purposes of determining whether § 448(a)(2) applies to any partnership
  • § 448(b)(3) gross receipts test. Paragraphs (1) and (2) of subsection (a) do not apply to any corporation or partnership meeting the § 448(c) gross receipts test for the taxable year
• § 448(c) gross receipts test. A corporation or partnership meets the gross receipts test if the average annual gross receipts for the 3-taxable-year period ending with the preceding taxable year do not exceed $25,000,000, indexed for inflation. For 2025, the threshold is $31,000,000. Rev. Proc. 2024-40, § 3.31. For 2026, the threshold is $32,000,000. Rev. Proc. 2025-32, § 4.30. Gross receipts of all persons treated as a single employer under § 52(a) and (b) or § 414(m) and (o) must be aggregated. Short taxable years are annualized. The test is applied on a year-by-year basis. The corporation must meet the test for the current taxable year to use the cash method.
• § 448(d)(2) QPSC definition. A qualified personal service corporation must satisfy two tests:
  • Function test (95% activities). Substantially all (interpreted by Treas. Reg. § 1.448-1T(e)(4) as 95% or more) of the corporation's activities involve the performance of services in one or more of eight fields. These are health, law, engineering (including surveying and mapping), architecture, accounting, actuarial science, performing arts, or consulting
  • Ownership test (95% by value). Substantially all of the stock (by value) is held directly or indirectly by employees performing services in a qualifying field, retired employees who had performed such services, estates of such employees (for a 2-year period beginning on the date of death), or persons who acquired stock by reason of the death of an employee within 2 years of the death
• § 448(d)(7) [formerly § 448(f)] change to accrual triggers § 481(a) adjustment. Any change in method of accounting required by § 448 is treated as a change initiated by the taxpayer with consent of the Secretary. The § 481(a) adjustment (the difference between income reported under the old method and what would have been reported under the new method as of the beginning of the year of change) is taken into account ratably over the shorter of 4 years or the period the taxpayer used the cash method. § 481(a)(2)(B)(i) and (ii). In Capital One Financial Corp. v. Commissioner, 130 T.C. 147 (2008), the Tax Court held that a taxpayer forced to change its method under § 448 must still file Form 3115 to effectuate the change.
• § 471 inventory rules and interplay. A C corporation that is not exempt under § 448(b)(3) and that maintains inventory must use the accrual method because § 471(a) requires inventory accounting, and the accrual method is necessary to properly account for inventory. However, § 471(c) exempts small business taxpayers (meeting the § 448(c) gross receipts test) from § 471(a) inventory requirements. Such taxpayers may (1) treat inventory as non-incidental materials and supplies under § 471(c)(1)(B)(i), (2) use the method in their applicable financial statements under § 471(c)(1)(B)(ii), or (3) use their books and records method consistent with how they report inventory on their financial statements. § 471(c)(1)(B).
• Rev. Proc. 2002-28 qualifying small business taxpayer. Revenue Procedure 2002-28 provided a cash method exception for certain small taxpayers with inventories and gross receipts of $10 million or less in eligible trades or businesses (retail, wholesale, certain services, manufacturing, and certain production activities). This revenue procedure has been largely superseded by TCJA amendments to § 448(c) and § 471(c) that expanded the cash method and simplified inventory exceptions to $25 million (now indexed). However, Rev. Proc. 2002-28 remains relevant for transitional guidance and for taxpayers ineligible for the § 471(c) simplified inventory method.
• TRAP. A C corporation that qualifies for the cash method under § 448(b)(3) (the gross receipts test) must still use the accrual method for purchases and sales if it is required to account for inventories, unless it qualifies for the § 471(c) small business inventory exception. A corporation cannot use the cash method for its general accounting while maintaining accrual-basis inventory records.
• CAUTION. The aggregation rule in § 448(c) means that a small C corporation with gross receipts below the threshold may be required to use the accrual method if it is treated as a single employer with related entities whose combined gross receipts exceed the threshold. Related entities include parent-subsidiary groups under § 52(a), brother-sister groups under § 52(b), and affiliated service groups under § 414(m).

Step 13. Corporate Tax Rates Under § 11

"The amount of the tax imposed by subsection (a) shall be 21 percent of taxable income." § 11(b).

• § 11(b) flat 21% rate. The Tax Cuts and Jobs Act amended § 11(b) to impose a flat 21% tax on all corporate taxable income, effective for tax years beginning after December 31, 2017. § 13001(a) of the TCJA. The rate is permanent with no sunset provision. The computation is straightforward. Taxable income multiplied by 21% equals the regular tax liability. There are no graduated brackets, no phase-outs, no surtaxes, and no zero-rate brackets.
• § 11(a) tax imposed. A tax is hereby imposed for each taxable year on the taxable income of every corporation. § 11(a). § 11(c) excludes corporations subject to tax under § 594 (mutual savings banks conducting life insurance business), subchapter L (insurance companies), and subchapter M (regulated investment companies and real estate investment trusts). These entities have their own rate structures.
• Pre-TCJA graduated rates (historical context). Prior to the TCJA, § 11(b)(1) provided a four-bracket graduated rate structure:
  • 15% on taxable income from $0 to $50,000
  • 25% on taxable income from $50,001 to $75,000
  • 34% on taxable income from $75,001 to $10,000,000
  • 35% on taxable income over $10,000,000
• Pre-TCJA surtaxes (eliminated). A 5% surtax applied to taxable income from $100,000 to $335,000, with a maximum surtax of $11,750. This effectively phased out the benefit of the 15% and 25% brackets so that corporations with taxable income between $335,000 and $10,000,000 effectively paid a flat 34% rate. A 3% surtax applied to taxable income from $15,000,000 to $18,333,333, with a maximum surtax of $100,000, effectively phasing out the benefit of the 34% rate so that corporations with taxable income above $18,333,333 effectively paid a flat 35% rate. Both surtaxes were eliminated by the TCJA.
• Pre-TCJA QPSC rate. Qualified personal service corporations were taxed at a flat 35% rate under pre-TCJA § 11(b)(2). The TCJA eliminated the special QPSC rate entirely. All QPSCs are now taxed at the same 21% flat rate as all other C corporations.
• § 11(d) foreign corporations. In the case of a foreign corporation, the taxes imposed by subsection (a) and section 55 shall apply only as provided by section 882. The reference to section 55 was restored by the Inflation Reduction Act of 2022 (§ 10101(a)(4)(C)) when the corporate AMT was reinstated for applicable corporations.
• IRA 2022 corporate AMT. The Inflation Reduction Act of 2022 enacted a new 15% corporate alternative minimum tax on adjusted financial statement income for applicable corporations with average annual adjusted financial statement income exceeding $1 billion (or $100 million in the case of foreign-parented multinational groups). § 55. This new AMT operates under § 55 but is fundamentally different from the repealed pre-TCJA corporate AMT which was based on alternative minimum taxable income with numerous preference items and adjustments. The new CAMT applies to the adjusted financial statement income of the corporation and its controlled subsidiaries.
• Fiscal year blending. For fiscal year corporations with tax years straddling January 1, 2018, § 15(a) required a blended rate computation. The blended rate equaled a weighted average of pre-TCJA rates and the 21% rate based on the number of days in each period. This issue is now of only historical interest as all tax years beginning after 2017 are fully subject to the 21% rate.
• EXAMPLE. Calendar year C Corporation has taxable income of $500,000 for 2025. The tax is $500,000 x 21% = $105,000. No surtaxes, no graduated brackets, no special computations. If taxable income is $5,000,000, the tax is $5,000,000 x 21% = $1,050,000. If taxable income is $50,000,000, the tax is $50,000,000 x 21% = $10,500,000. The rate is flat and uniform across all income levels.
• TRAP. Corporations should not assume that the flat 21% rate eliminates the need for careful tax planning. The effective tax rate can exceed 21% when BEAT applies, the IRA 2022 CAMT applies, state income taxes are considered, or when timing differences (such as the 80% NOL limitation) push income into higher-rate years.

Step 14. General Business Credit and Foreign Tax Credit

• § 38 general business credit. The general business credit is an aggregation of specific credits listed in § 39(b), including the investment tax credit (§ 46 and § 48), work opportunity credit (§ 51), alcohol fuels credit (§ 40), research credit (§ 41), low-income housing credit (§ 42), disabled access credit (§ 44), empowerment zone employment credit, renewable energy production credit (§ 45), employer-provided child care credit (§ 45F), small employer health insurance credit (§ 45R), and other specific credits. Each credit has its own eligibility requirements, computation rules, and limitations.
• § 38(c) GBC limitation. The general business credit for any taxable year is limited to the excess of (1) the net income tax over the greater of (A) the tentative minimum tax or (B) 25% of so much of the net regular tax liability as exceeds $25,000. § 38(c)(1). The $25,000 amount is reduced for controlled groups under § 38(c)(3)(B). Net income tax means the sum of the regular tax liability and the tax imposed by § 55 (the IRA 2022 CAMT for applicable corporations), reduced by the credits allowable under subpart A and section 27 (the foreign tax credit). The GBC limitation ensures that credits cannot offset more than 75% of regular tax liability above $25,000.
• § 39 carryback and carryforward. Current-year business credits that exceed the § 38(c) limitation may be carried back 1 year and forward 20 years. § 39(a)(1)(A) and (B). The GBC is applied on a FIFO basis, meaning carryover credits from the earliest available year are applied first against the current-year limitation, then current-year credits, then credits from later years. Unused credits after the 20-year carryforward period expire and may not be used.
• § 901 direct foreign tax credit. A domestic corporation that pays or accrues income, war profits, and excess profits taxes to a foreign country or U.S. possession may credit those taxes against U.S. tax liability. § 901(b). The foreign tax credit is elective. The taxpayer may instead deduct the foreign taxes under § 164(a)(3) in the year paid or accrued. Once the election to credit is made for a given year, it generally applies to all foreign taxes for that year. The election is binding and must be made on the original return.
• § 904 FTC limitation. The foreign tax credit is limited to the U.S. tax attributable to foreign-source taxable income. § 904(a). The limitation is computed separately for each basket of income. § 904(d)(1) currently provides four baskets. These are (1) passive category income, (2) general category income, (3) global intangible low-taxed income (GILTI), and (4) foreign branch income. Excess credits in one basket generally cannot offset U.S. tax on income in another basket (though limited cross-crediting is permitted within the general category for certain high-taxed income). Excess credits may be carried back 1 year and forward 10 years. § 904(c). Taxpayers may elect to claim the FTC on an overall basis or on a per-country basis. § 904(j).
• § 250(a) FDII and GILTI deductions. For tax years beginning before January 1, 2026, § 250(a)(1) allows domestic corporations a deduction equal to the sum of:
  • 37.5% of foreign-derived intangible income (FDII), plus
  • 50% of the global intangible low-taxed income (GILTI) inclusion amount plus the § 78 gross-up attributable to GILTI

For tax years beginning after December 31, 2025, OBBBA changes the framework:

• 33.34% of foreign-derived deduction eligible income (FDDEI, formerly FDII), plus
• 40% of net CFC tested income (NCTI, formerly GILTI)

• § 250(a)(2) taxable income limitation. If the sum of FDII/NCTI and GILTI exceeds taxable income (determined without regard to § 250), the amounts are reduced proportionally before applying the deduction percentages. This limitation ensures that the § 250 deduction cannot create or increase an NOL.
• § 59A BEAT interaction. The base erosion and anti-abuse tax may apply to corporations that claim substantial foreign tax credits because BEAT is computed before many credits reduce regular tax liability. § 59A(b)(1)(B) provides that the base erosion minimum tax amount is reduced by the excess of regular tax liability over the base erosion minimum tax amount, but certain credits (including FTCs) are added back for this computation. A corporation subject to both BEAT and the FTC limitation must perform both computations simultaneously.
• TRAP. The general business credit carryback period is only 1 year (not 2 years like pre-2018 NOLs). If a corporation had no tax liability in the prior year, the current-year credit must be carried forward. Credits that expire after 20 years of carryforward provide no benefit.

Step 15. Corporate Alternative Minimum Tax and BEAT

• § 55 corporate AMT was repealed by TCJA then reinstated by IRA 2022. The Tax Cuts and Jobs Act repealed the corporate alternative minimum tax for tax years beginning after December 31, 2017. § 12001(a)(1) of the TCJA. The Inflation Reduction Act of 2022 enacted a new 15% corporate alternative minimum tax on adjusted financial statement income (AFSI) for applicable corporations with average annual AFSI exceeding $1 billion. § 55(a)(2). This new AMT operates under § 55 but is fundamentally different from the repealed pre-TCJA corporate AMT which was based on alternative minimum taxable income with numerous preference items and adjustments. The new CAMT applies to the adjusted financial statement income of the corporation and its controlled subsidiaries.
• Applicable corporation test. An applicable corporation is any corporation (other than an S corporation, regulated investment company, or real estate investment trust) whose average annual AFSI for the 3-taxable-year period ending with the preceding taxable year exceeds $1,000,000,000. For foreign-parented multinational groups, a lower $100,000,000 threshold applies if the group's worldwide AFSI exceeds $1,000,000,000. § 59(k).
• § 53 minimum tax credit carryforwards still usable. Corporations with minimum tax credit carryovers from pre-2018 tax years can still use those credits to offset regular tax liability. The CARES Act (§ 2305) made 100% of remaining excess minimum tax credits refundable for tax years beginning after 2018, with full refundability by 2021. Most pre-2018 MTCs have now been fully utilized or refunded. § 53(e).
• § 59A BEAT applicable to certain corporations. The base erosion and anti-abuse tax applies to applicable taxpayers that make base erosion payments to foreign related parties. BEAT was enacted by the TCJA as a backstop to prevent erosion of the U.S. tax base through deductible payments to foreign affiliates.
• § 59A(e) applicable taxpayer requirements. A corporation is an applicable taxpayer only if:
  • It is a corporation (not a RIC, REIT, or S corporation)
  • Average annual gross receipts for the 3-taxable-year period ending with the preceding taxable year are $500,000,000 or more. § 59A(e)(3)
  • The base erosion percentage is 3% or greater (2% for banks and registered securities dealers). § 59A(e)(1)(C)
• Base erosion percentage. The base erosion percentage for any taxable year is the aggregate amount of base erosion tax benefits for the taxable year divided by the aggregate amount of deductions allowable to the taxpayer for the taxable year, plus certain other base erosion amounts. § 59A(c)(4).
• § 59A(b) BEAT computation. The BEAT equals the excess (if any) of the applicable BEAT rate multiplied by the taxpayer's modified taxable income over the taxpayer's regular tax liability adjusted as provided in § 59A(b)(2). The regular tax liability is reduced by all credits other than the research credit (and certain other specified credits), and then increased back by the amount of credits disallowed.
• BEAT rates. Pub. L. 119-21 (OBBBA) changed the BEAT rate framework. The standard rate is 10.5% and the bank/dealer rate is 11.5% for the applicable period after July 2025.
• § 59A(e) modified taxable income. Modified taxable income equals regular taxable income plus base erosion tax benefits. § 59A(c)(1). Base erosion tax benefits include deductions for amounts paid or accrued to foreign related parties, depreciation or amortization deductions for property acquired from foreign related parties, reinsurance payments to foreign related parties, and payments to expatriated entities. § 59A(d). The base erosion tax benefit is the amount of any deduction allowed under chapter 1 for the taxable year with respect to any base erosion payment.
• TRAP. BEAT is computed as an additional tax, not as an alternative minimum tax. BEAT paid generates no credits that can offset future regular tax liability. Unlike the old corporate AMT, which generated minimum tax credits usable against future regular tax, BEAT is purely an additional tax burden with no future benefit.
• CAUTION. BEAT can apply even when a corporation has no regular tax liability if the corporation has sufficient tax credits to reduce regular tax to zero. BEAT is computed on modified taxable income, not on regular taxable income. A corporation with positive modified taxable income and substantial credits may owe BEAT even with zero regular tax liability.

Step 16. Accumulated Earnings Tax and Personal Holding Company Tax

• § 531 AET is 20% on accumulated taxable income. § 531 imposes an accumulated earnings tax equal to 20% of the corporation's accumulated taxable income. § 531. The AET applies to every corporation formed or availed of for the purpose of avoiding income tax with respect to its shareholders by permitting earnings and profits to accumulate instead of being divided or distributed. § 532(a). The AET does not apply to personal holding companies (taxed under § 541), tax-exempt corporations, or passive foreign investment companies. § 532(b). No estimated tax penalties apply to the AET. The IRS bears the initial burden of proving that the corporation was availed of for tax avoidance purposes, though § 533 creates a rebuttable presumption when earnings accumulate beyond the reasonable needs of the business. Ivan Allen Co. v. United States, 422 F.2d 197 (5th Cir. 1970) (court evaluates whether accumulation was motivated by shareholder tax avoidance).
• § 535 accumulated taxable income computation. Accumulated taxable income equals taxable income for the taxable year with certain adjustments under § 535(b), minus the dividends paid deduction under § 561 and the accumulated earnings credit under § 535(c). Key § 535(b) adjustments to taxable income include adding back federal income taxes paid or accrued, allowing charitable contributions without the § 170(b)(2) 10% limitation, disallowing the DRD and § 250 deduction, disallowing the NOL deduction except to the extent it offsets income from the same taxable year, subtracting net capital gain (the excess of net long-term capital gain over net short-term capital loss) and the tax attributable to such gain, and certain other adjustments.
• § 535(c) accumulated earnings credit. The credit equals the amount of earnings retained for the reasonable needs of the business, with a minimum credit of $250,000 ($150,000 for certain service corporations described in § 535(c)(2)(B) that provide services in health, law, engineering, architecture, accounting, actuarial science, performing arts, or consulting). § 535(c)(2). A mere holding or investment company is limited to the statutory minimum only. § 535(c)(3). For controlled groups, the $250,000/$150,000 amount is divided equally among component members. § 1561(a). The accumulated earnings credit operates as an offset against accumulated taxable income, reducing the amount subject to the 20% tax.
• § 537 reasonable needs of the business. Reasonable needs of the business includes the reasonably anticipated needs of the business, § 303 redemption needs (to redeem stock included in a decedent's gross estate), and excess business holdings redemption needs under § 302(c)(2)(A)(iii). § 537(a). Treas. Reg. § 1.537-2 identifies bona fide expansion of business or replacement of plant, acquisition of a business, debt retirement, working capital, investments or loans necessary to the business, and product liability loss reserves as potential reasonable business needs. The reasonable needs standard is subjective and based on the particular facts and circumstances of each case.
• § 541 PHC tax is 20% on undistributed PHC income. § 541 imposes a personal holding company tax equal to 20% of the corporation's undistributed personal holding company income. § 541. The PHC tax is self-assessing (the corporation determines its own PHC status and reports any tax liability on Schedule PH of Form 1120) and is imposed in addition to the regular corporate income tax. The PHC tax is designed to discourage the use of a corporate entity to shelter personal investment income from individual-level tax.
• § 542 PHC definition. A corporation is a personal holding company only if it meets both tests:
  • Income test (60% PHCI). At least 60% of adjusted ordinary gross income is personal holding company income. § 542(a)(1)
  • Ownership test (>50% by not more than 5 individuals). At any time during the last half of the taxable year, more than 50% in value of outstanding stock is owned directly or indirectly by or for not more than 5 individuals. § 542(a)(2)
• § 543 PHC income categories. Personal holding company income includes dividends, interest (subject to exceptions), royalties (non-mineral), annuities, rents (subject to exceptions), mineral royalties, copyright royalties, produced film rents, compensation for use of corporate property by 25% or greater shareholders, personal service contract income, and estate or trust income. § 543(a).
• § 544 constructive ownership rules. For purposes of the 5-individual, 50%+ stock ownership test, § 544(a) applies family attribution (spouse, brothers, sisters, ancestors, lineal descendants), partnership attribution, estate and trust attribution, and options to acquire stock. These constructive ownership rules can cause stock held by related parties to be aggregated for purposes of the ownership test, making it more likely that a closely held corporation will be classified as a PHC.
• § 546 deficiency dividend procedure. If a determination (including a Tax Court decision, settlement, or final administrative determination) establishes PHC tax liability, the corporation may pay deficiency dividends within 90 days after the determination and file a claim within 120 days to avoid the PHC tax (though interest and penalties from the original due date still apply). Form 976 is used to claim the deficiency dividends deduction. This procedure allows corporations to escape the PHC tax by making retroactive dividend distributions, but the interest charge preserves the time value of money benefit to the government.
• TRAP. A closely held investment corporation that is not a PHC may still be subject to the AET. The AET and PHC tax are mutually exclusive (§ 532(b)(1) excludes PHCs from the AET), but a corporation not meeting the PHC definition (perhaps because it has fewer than 60% PHCI or the ownership test is not met) may face AET liability if it accumulates earnings beyond reasonable business needs. Practitioners should evaluate both regimes when advising closely held corporations with significant retained earnings.

Step 17. Tax Credit Summary and Ordering

• Order of credit application. Credits are applied against tax liability in the following general order established by the Code structure:
  1. Foreign tax credit under § 27 and § 901 (subpart A of part IV of subchapter A)
  2. General business credit under § 38 (aggregation of specific credits under § 39)
  3. Prior year minimum tax credit under § 53
  4. Other nonrefundable credits under subpart C of part IV (various)
• Refundable vs. nonrefundable credits. Most corporate tax credits are nonrefundable (they can reduce tax liability to zero but not below). The following refundable credits are relevant to C corporations:
  • Minimum tax credit under § 53(e) (fully refundable for tax years beginning after 2018 per CARES Act § 2305)
  • Credit for federal tax paid on fuels under § 34
  • Wage withholding credit under § 31 (for corporations with employees)

Nonrefundable credits that reduce tax liability but cannot create a refund include the foreign tax credit, the general business credit (and all component credits), the orphan drug credit, and the disabled access credit.

• Carryback and carryforward rules.
  • General business credit under § 38 is carryback 1 year and forward 20 years. § 39(a)(1)
  • Foreign tax credit under § 901 is carryback 1 year and forward 10 years. § 904(c)
  • Minimum tax credit under § 53 has indefinite carryforward. § 53(b). Excess credits are refundable through 2021 per CARES Act
• Credit ordering within the GBC. Within the general business credit, component credits are applied in a specific order prescribed by § 38(b) and § 39. The research credit, low-income housing credit, and rehabilitation credit are among the most commonly claimed GBC components.
• CAUTION. The § 38(c) GBC limitation must be computed before applying any carryovers. Current-year credits are applied first against the limitation, then carryover credits from the earliest available year. A corporation that expects to generate GBCs in excess of the limitation should consider strategies to increase regular tax liability in those years, such as accelerating income or deferring deductions, to absorb more credits.

Step 18. Estimated Tax Payments and Filing Obligations

"Except as otherwise provided in this section, in the case of any underpayment of estimated tax by a corporation, there shall be added to the tax under chapter 1 for the taxable year an amount determined by applying (1) the underpayment rate established under section 6621, (2) to the amount of the underpayment, (3) for the period of the underpayment." § 6655(a).

• § 6655 estimated tax requirements. A corporation must make estimated tax payments if its tax (income tax minus credits) is $500 or more. § 6655(f). Estimated tax includes regular tax under § 11, the corporate AMT under § 55 (IRA 2022 CAMT for applicable corporations), and BEAT under § 59A. § 6655(g)(1). The estimated tax penalty is imposed as an addition to tax at the federal short-term rate plus 3 percentage points (compounded daily). § 6621(a)(2).
• Due dates on the 15th of the 4th, 6th, 9th, and 12th months. Four equal installments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the taxable year. § 6655(c)(2). For calendar year corporations, the due dates are April 15, June 15, September 15, and December 15. If a due date falls on a weekend or legal holiday, the payment is due on the next business day.
• § 6655(d)(1)(B) 100% prior year safe harbor. The required annual payment is the lesser of 100% of the tax shown on the current year return or 100% of the tax shown on the prior year return, provided the prior year was a 12-month taxable year and a return was filed showing a tax liability. § 6655(d)(1)(B). This safe harbor provides certainty because the corporation can base its estimates on a known prior-year amount without needing to predict current-year income.
• § 6655(d)(2) large corporation exception. A large corporation (one that had taxable income of $1,000,000 or more in any taxable year during the 3-year testing period) may not use the prior year safe harbor for any installment except the first. § 6655(d)(2)(A). The $1,000,000 amount is divided among controlled group members under § 6655(g)(2)(C). For the first installment only, the large corporation may use the prior year safe harbor, but any resulting underpayment from lower first-quarter estimates is recaptured by increasing subsequent required installments. § 6655(d)(2)(B). A large corporation must generally estimate its current-year tax liability and pay based on the annualized income method or current year method.
• § 6655(e) annualized income method. Corporations with seasonal or uneven income may use the annualized income installment method or the adjusted seasonal installment method to reduce estimated tax payments in early quarters when income is lower. § 6655(e)(1) and (2). The annualized income method requires computing taxable income for the period ending before each installment due date and annualizing it. Form 2220 provides the annualization schedules.
• § 6655(g)(3) 100% current year safe harbor. In lieu of the prior year safe harbor, a corporation may base its estimated tax payments on 100% of the current year's tax liability. This is inherently uncertain because the corporation must estimate its tax liability before the year ends. Underestimation results in penalty exposure for the underpaid quarters.
• § 6072(a) return due date. Returns for C corporations are due on the 15th day of the 4th month following the close of the taxable year (April 15 for calendar year corporations). § 6072(a). Fiscal year corporations file on the 15th day of the 4th month following the fiscal year end.
• § 6081 automatic 6-month extension. C corporations filing Form 7004 receive an automatic 6-month extension to file (October 15 for calendar year corporations). § 6081(b). However, an extension to file is NOT an extension to pay. Estimated tax must still be paid by the original due date to avoid the failure to pay penalty and interest. The extension must be filed by the original due date.
• § 6651(a)(1) failure to file penalty. A penalty of 5% of the unpaid tax per month (or fraction thereof) up to a maximum of 25% is imposed for failure to file a return by the due date. § 6651(a)(1). For returns more than 60 days late, the minimum penalty is the lesser of the applicable dollar amount or 100% of the tax due. § 6651(a)(1) flush language. For returns due in 2025, the minimum penalty is $510. The penalty is waived if the failure is due to reasonable cause and not willful neglect. § 6651(a).
• § 6651(a)(2) failure to pay penalty. A penalty of 0.5% of the unpaid tax per month (or fraction thereof) up to a maximum of 25% is imposed for failure to pay the amount shown on the return. § 6651(a)(2). The rate increases to 1% per month after notice of intent to levy is issued. § 6651(d).
• § 6662 accuracy-related penalty. A penalty of 20% of the underpayment attributable to the relevant conduct is imposed for negligence, substantial understatement of income tax, substantial valuation misstatement, transactions lacking economic substance, or undisclosed foreign financial asset understatements. § 6662(a). For corporations, a substantial understatement exists if the understatement exceeds the lesser of 10% of the tax required to be shown on the return or $10,000,000. § 6662(d)(1). No accuracy-related penalty is imposed if the taxpayer shows reasonable cause and acted in good faith. § 6664(c)(1).
• Form 1120 filing package. Every domestic corporation must file Form 1120 unless exempt under § 501 (tax-exempt organizations). Key schedules and forms include the following.
  • Schedule C, Dividends and Special Deductions (DRD computation and limitations).
  • Schedule J, Tax Computation (including regular tax, credits, and other taxes).
  • Schedule K, Other Information (25+ questions including accounting method, business activity, ownership, and payments to individuals).
  • Schedule L, Balance Sheets per Books (assets, liabilities, and equity at beginning and end of year).
  • Schedule M-1 or M-3, Reconciliation of Income (Loss) per Books With Income per Return.
  • Schedule M-2, Analysis of Unappropriated Retained Earnings per Books.
• Schedule M-1 vs. M-3. Corporations with total assets at the end of the taxable year below $10 million complete Schedule M-1. Corporations with total assets of $10 million or more must complete Schedule M-3 (Net Income (Loss) Reconciliation for Corporations with Total Assets of $10 Million or More). Large corporations (with $50 million or more in assets) must complete Schedule M-3 in its entirety, including separate line items for book-tax differences for each material item. Schedule M-3 provides much greater transparency to the IRS about book-tax differences.
• § 1502 consolidated return election. An affiliated group (a common parent corporation plus one or more includible subsidiary corporations meeting the 80% vote and value ownership test of § 1504(a)) may elect to file a single consolidated return on Form 1120. The election is made by filing Form 1120 with Form 851 (Affiliations Schedule) attached and is binding for all subsequent years unless the group terminates (by all members ceasing to be includible, the common parent ceasing to be a member, or the group filing a final consolidated return). The common parent acts as sole agent for all members in all matters relating to the consolidated return. Treas. Reg. § 1.1502-75(a)(2). Intercompany transactions and dividends are generally eliminated in consolidation.
• TRAP. The extension for calendar year C corporations was 5 months (not 6 months) for taxable years beginning before January 1, 2026. § 6072(a) changed the due date from the 15th day of the 3rd month to the 15th day of the 4th month for taxable years beginning after December 31, 2015, and the corresponding extension period changed from 6 months to 5 months (September 15 for calendar year corporations filing for years beginning before 2026). For taxable years beginning after December 31, 2025, the full 6-month extension applies (October 15). § 6081(b).

Step 19. Controlled Groups and Special Limitations

• § 1561 allocation of accumulated earnings credit. The component members of a controlled group of corporations are limited to one $250,000 amount ($150,000 if any component member is a service corporation described in § 535(c)(2)(B) that provides services in health, law, engineering, architecture, accounting, actuarial science, performing arts, or consulting) for purposes of computing the accumulated earnings credit under § 535(c)(2) and (3). § 1561(a). The amount is divided equally among component members unless the Secretary prescribes regulations permitting an unequal allocation. The equal allocation is mandatory unless the group files a written agreement to apportion unequally. Treas. Reg. § 1.1561-2.
• § 1563 controlled group definitions. § 1563 defines three types of controlled groups for federal tax purposes.
  • Parent-subsidiary controlled group. One or more chains of corporations connected through stock ownership with a common parent if the parent owns at least 80% of the total combined voting power and at least 80% of the total value of at least one includible corporation (other than the parent), and at least 80% of the total combined voting power and at least 80% of the total value of each other corporation (except the parent) is owned by one or more of the other corporations. § 1563(a)(1)
  • Brother-sister controlled group. Two or more corporations if five or fewer individuals, estates, or trusts own stock possessing at least 80% of the total combined voting power or total value of each corporation and more than 50% of the total combined voting power or total value of each corporation, taking into account only identical ownership. § 1563(a)(2)
  • Combined controlled group. Three or more corporations each of which is a member of a parent-subsidiary or brother-sister group, and one of which is a common parent or corporation included in both groups. § 1563(a)(3)
• Component member defined. A component member of a controlled group is any corporation included in the group on December 31 of the taxable year (the statutory date), or that was included for at least one-half of the number of days in its taxable year that fall within the calendar year and was not excluded as a transient member. § 1563(b).
• § 1561 limitations on multiple benefits. § 1561(a) also imposes limitations on the following tax benefits across controlled group members.
  • The graduated corporate rate brackets (now moot with the flat 21% rate)
  • The § 179 expense election limitation
  • The § 926 AMT exemption amounts (now moot with repeal of the old corporate AMT)
• § 1551 prohibition on splitting to secure benefits was repealed by TCJA. § 1551, which disallowed the benefits of graduated corporate rates and the accumulated earnings credit for corporations formed or used to avoid tax through corporate splitting, was repealed by TCJA § 13001(b)(5)(A). The repeal was logical because the TCJA replaced the graduated rate structure with a flat 21% rate, eliminating the benefit of rate splitting that § 1551 was designed to prevent. The accumulated earnings credit limitation is now addressed solely through § 1561(a).
• TRAP. Although § 1551 was repealed, the IRS may still challenge multiple corporations formed primarily to secure tax benefits under the judicially-created step transaction doctrine, substance-over-form principles, or § 269 (acquisitions made to evade or avoid tax). § 269(a) provides that if any person acquires control of a corporation and the principal purpose is tax evasion or avoidance, the IRS may disallow the resulting tax benefit.
• CAUTION. The controlled group rules in § 1563 apply independently from the affiliated group rules in § 1504. A controlled group may include corporations that are not members of the same affiliated group. For example, two brother-sister corporations that do not have a common parent cannot file a consolidated return under § 1502 but are still a controlled group subject to § 1561 limitations. Controlled group status must be evaluated separately from consolidated return eligibility.

Step 20. Documentation and Record Retention

• Contemporaneous documentation requirements. Every position taken on a corporate tax return should be supported by contemporaneous documentation created at or near the time the relevant events occurred. Key documentation includes:
  • Detailed workpapers supporting all items of taxable income
  • Documentation of all elections and the authority for each election
  • Supporting schedules for depreciation and amortization (asset basis, recovery period, convention, placed-in-service date, business use percentage, § 179 expense, bonus depreciation)
  • Minutes, board resolutions, and written authorizations for corporate elections including accounting method changes, § 481(a) adjustments, and § 179 elections
  • Ownership records for DRD qualification (vote and value percentages on dividend receipt date)
• Form 1120 filing package. The complete Form 1120 filing should include:
  • Form 1120 with all applicable schedules (C, J, K, L, M-1 or M-3, M-2)
  • Form 4562 (Depreciation and Amortization) if claiming depreciation, § 179 expense, or amortization
  • Form 4797 (Sales of Business Property) if any business assets were sold or disposed of during the year
  • Form 8990 (Limitation on Business Interest Expense Under § 163(j)) if business interest expense exceeds business interest income
  • Form 8993 (§ 250 Deduction for Foreign-Derived Intangible Income and Global Intangible Low-Taxed Income) if claiming FDII or GILTI deductions
  • Form 8991 (Tax on Base Erosion Payments of Taxpayers With Substantial Gross Receipts) if potentially subject to BEAT
  • Form 8992 (U.S. Shareholder Calculation of Global Intangible Low-Taxed Income) if the corporation is a U.S. shareholder of CFCs
  • Form 8996 (Qualified Opportunity Fund) if the corporation invested in a QOF
  • Form 2220 (Underpayment of Estimated Tax by Corporations) if computing estimated tax penalties
  • Any required elections attached as separate statements to the return
• Supporting workpapers for all computations. Maintain detailed workpapers for:
  • Taxable income computation line-by-line, tracing each item from the general ledger to the tax return
  • NOL deduction computation showing NOL vintage (pre-2018 vs. post-2017), carryover year, amount utilized, 80% limitation computation, and remaining balance for each vintage
  • DRD computation showing ownership percentage, DRD tier, holding period verification, and § 246(b) taxable income limitation
  • § 163(j) limitation computation showing ATI, business interest income, business interest expense, 30% of ATI, and any excess business interest carryforward
  • Charitable contribution computation showing 10% limitation, property type (cash, ordinary income property, capital gain property), § 170(e)(3) enhanced deduction, and carryforward tracking
  • Estimated tax computation showing safe harbor analysis (prior year, current year, annualized income), large corporation status, and penalty computation
• DRD holding period documentation. For every dividend for which the DRD is claimed, maintain documentation establishing that the stock was held for more than 45 days during the 91-day period beginning 45 days before the ex-dividend date. § 246(c)(1)(A). For § 245A foreign-source dividends from 10%-owned foreign corporations, document that the stock was held for more than 365 days during the 731-day period beginning 365 days before the ex-dividend date. § 246(c)(5). Document any reductions under § 246A for debt-financed portfolio stock by maintaining records of average indebtedness and average basis.
• NOL carryforward tracking schedules. Maintain a detailed NOL tracking schedule for each NOL vintage showing:
  • Year of origin and original NOL amount
  • Amount utilized in each carryover year with citation to the return
  • Remaining balance at the end of each year
  • Application of 80% limitation where applicable
  • § 382 limitation computation if an ownership change occurred under § 382(g)
  • State NOL computations separate from federal for non-conforming states
• § 481(a) adjustment documentation for accounting method changes. If the corporation changes its method of accounting (including a change from cash to accrual required by § 448, a change in depreciation method, a change in inventory method, or any other change requiring IRS consent), maintain documentation of:
  • The § 481(a) adjustment amount (the net adjustment required to prevent duplication or omission of income)
  • The spreading period (4 years or the period the taxpayer used the old method, whichever is shorter) for an involuntary change. The taxpayer may elect to take the full adjustment in the year of change for a voluntary change
  • Form 3115 (Application for Change in Accounting Method) filed with the original return or separately
  • The specific Code section and regulation authority for the change

In Capital One Financial Corp. v. Commissioner, 130 T.C. 147 (2008), the Tax Court held that a taxpayer forced to change its method of accounting under § 448 must still file Form 3115 to effectuate the change. The IRS has authority to impose terms and conditions on the change.

• Statute of limitations considerations. The statute of limitations for assessment of corporate tax is generally three years from the later of the return due date or the date the return was filed. § 6501(a). If a corporation omits from gross income an amount properly includible in gross income that exceeds 25% of the gross income stated on the return, the limitation period extends to six years. § 6501(e)(1)(A)(i). If a corporation files a false or fraudulent return with intent to evade tax, or if no return is filed, there is no statute of limitations. § 6501(c). Keep all supporting documentation for at least the applicable limitation period plus a reasonable margin (generally 7 years for conservative practice).
• TRAP. The Supreme Court in Beard v. Commissioner, 82 T.C. 766 (1984), aff'd 793 F.2d 139 (6th Cir. 1986), held that a document is not a valid return unless it purports to be a return, is executed under penalties of perjury, contains sufficient data to calculate tax liability, and represents an honest and reasonable attempt to satisfy the law. A Form 1120 that lacks a signature, that contains materially false information, or that is filed in a manner that prevents the IRS from processing it may not start the statute of limitations.