Amortization Meaning: Definition, Formula & Form 4562

What Amortization Means on Your Business Tax Return

While "amortization" in everyday finance refers to paying off a loan in regular principal-and-interest installments, in business accounting and federal tax law it means writing off intangible assets and capital costs in equal amounts over a fixed recovery schedule. According to IRS Publication 946 (2025), Section 197 intangibles cannot be depreciated at all and must be amortized instead.

When you dispose of a Section 197 intangible, it is treated as depreciable property used in your trade or business. Any gain on the disposition, up to the amount of allowable amortization, is recaptured as ordinary income. If you dispose of multiple Section 197 intangibles in a single transaction or a series of related transactions, you calculate recapture as if all of those intangibles were a single asset, unless the adjusted basis of an intangible exceeds its fair market value.

• IRS: Instructions for Form 4562 (2025)
• IRS: Publication 946 (2025), How To Depreciate Property

What Costs Can Be Amortized and Their Recovery Periods

The Internal Revenue Code assigns specific recovery periods and starting rules to each category of amortizable cost reported on Part VI of Form 4562.

• Section 197 intangibles: Amortized over 180 months, starting with the later of the month the intangibles were acquired or the month your trade, business, or income-producing activity begins. This covers goodwill, going concern value, workforce in place, business books and records, operating systems, customer-based and supplier-based intangibles, government licenses or permits, covenants not to compete acquired with a business, and franchises, trademarks, or trade names (including renewals).
• Business startup and organizational costs: Includes business startup costs (Section 195), corporate organizational costs (Section 248), and partnership organizational costs (Section 709). For costs paid or incurred after September 8, 2008, you can elect to deduct a limited amount in the year your business begins without attaching a separate statement. Any cost not deducted currently must be amortized ratably over a 180-month period starting with the month you begin business operations.
• Research and experimental expenditures (Sections 174 and 174A): Under P.L. 119-21 for tax years beginning in 2025, domestic research or experimental expenditures (including software development) can be deducted as current business expenses. Alternatively, you can elect to capitalize and amortize domestic research expenditures equally over 60 months or more (starting the month you first realize benefits) or over a 10-year period. Foreign research expenditures conducted outside the United States, Puerto Rico, or U.S. territories must be capitalized and amortized ratably over a 15-year period beginning with the midpoint of the tax year in which they were paid or incurred.
• Certain created intangibles: Certain intangibles created on or after December 31, 2003 (such as amounts paid to acquire trade association memberships or privileges of indefinite duration) can be amortized over a 15-year period using the straight-line method and no salvage value, or 25 years for certain intangibles related to real property improvements.
• Cost of acquiring a business lease (Section 178): Amortized over the term of the lease. The lease term generally includes all renewal options unless 75% or more of the acquisition cost is for the remaining lease term on the acquisition date (excluding renewal periods).

• IRS: Instructions for Form 4562 (2025)
• IRS: Publication 946 (2025), How To Depreciate Property

How to Calculate Amortization: Formula and Worked Example

Part VI, Line 42, column (f) of Form 4562 gives two ways to compute your current-year amortization deduction. First, you can divide your total amortizable amount (column (c)) by the total number of months in the amortization period, and then multiply that monthly figure by the number of months of the amortization period included in your 2025 tax year. Second, if an annual percentage applies in column (e), you can multiply the amortizable amount in column (c) by that percentage.

Worked Example (Our calculation from the Form 4562 Part VI formula): Suppose your calendar-year business acquires a Section 197 customer list and trademark package for $90,000 as part of a business acquisition in July 2025, when your business is already operating. Because Section 197 intangibles must be amortized over 180 months starting in the month acquired, your amortization period begins in July 2025.

By our calculation from the Part VI formula, dividing the $90,000 amortizable amount in column (c) by 180 months gives $500 per month (1/180, or about 0.5556% of the total cost), and a full 12-month tax year equals $6,000 (12/180, or 6.67% of the total cost). Because July through December includes 6 months in your 2025 tax year, your 2025 deduction on Line 42, column (f) is $3,000 ($500 multiplied by 6 months, or 6/180). On Line 42, you enter "Section 197 customer list and trademark" in column (a), "07/2025" in column (b), "$90,000" in column (c), "197" in column (d), "180 months" in column (e), and "$3,000" in column (f). For every full 12-month calendar tax year from 2026 through 2039, you deduct $6,000 per year (12/180), and in your final year (2040), you deduct the remaining 6 months, which is $3,000 (6/180).

• IRS: Instructions for Form 4562 (2025)
• IRS: 4562 Depreciation and Amortization OMB No. 1545-0172

Amortization vs. Depreciation: How the IRS Separates Them

Both depreciation and amortization recover the cost of business or income-producing property over time, and both are calculated on Form 4562. However, the IRS applies different rules depending on whether an asset is tangible property, a non-Section 197 intangible, or a Section 197 intangible.

Depreciation generally applies to tangible property (such as buildings, machinery, vehicles, furniture, and equipment) using the Modified Accelerated Cost Recovery System (MACRS), which includes both declining-balance and straight-line methods. Depreciation also applies to specific intangible property that is not a Section 197 intangible.

For example, off-the-shelf computer software (readily available for purchase by the general public, subject to a nonexclusive license, and not substantially modified) is not a Section 197 intangible. Instead, it is depreciated using the straight-line method over 36 months on Line 16 of Form 4562, and may also qualify for the Section 179 deduction or special depreciation allowance. Similarly, residential mortgage servicing rights are depreciated over 108 months on Line 16, and patents or copyrights not acquired as part of a business are depreciated over their remaining legal life using the straight-line method (or the income forecast method). In contrast, patents, copyrights, or customized software acquired as part of buying a business are Section 197 intangibles and must be amortized over 180 months in Part VI.

• IRS: Publication 946 (2025), How To Depreciate Property
• IRS: Instructions for Form 4562 (2025)

Tax Forms and Lines That Use Amortization (Form 4562 Checklist)

When you claim amortization on a federal business return, where you report the deduction depends on whether the amortization starts in the current tax year or began in an earlier year. Use this checklist to file accurately.

• Check if you must file Form 4562: You are required to complete and attach Form 4562 if you are claiming amortization of costs that begins during your 2025 tax year, or if you are claiming any depreciation or amortization on a corporate income tax return (other than Form 1120-S).
• Report new 2025 amortization on Line 42: Enter a description of the costs in column (a), the date the amortization period begins in column (b), the total amortizable amount in column (c), the Internal Revenue Code section in column (d), the amortization period or percentage in column (e), and your amortization deduction for the year in column (f).
• Check if you need Form 4562 for prior-year amortization: If you are only reporting amortization of costs (other than research or experimental expenditures) that began before your 2025 tax year and you do not have to file Form 4562 for any other reason, do not file Form 4562. Instead, report the prior-year amortization deduction directly on the 'Other Deductions' or 'Other Expenses' line of your tax return.
• Report prior-year amortization on Line 43 when filing Form 4562: If you are already filing Form 4562 (or if you are reporting prior-year research or experimental expenditure amortization under Section 174 or Section 59(e)), enter the prior-year amortization on Line 43.
• Carry the Line 44 total to your tax return: Add column (f) of Lines 42 and 43 on Line 44, and report that total amortization on the applicable 'Other Deductions' or 'Other Expenses' line of your business tax return (such as Schedule C (Form 1040), Form 1065, or Form 1120-S).
• Check special reporting forms: Partnerships and S corporations must report the amortizable basis of any forestation or reforestation expenses elected under Section 194, along with the year amortization begins, as a separately stated item on Schedules K and K-1 (Form 1065 or Form 1120-S). Timber filers required to file Form T (Timber) can make the Section 194 reforestation election in Part IV of Form T. Individuals reporting bond premium amortization for taxable bonds acquired before October 23, 1986, or final accrual period carryforwards use Schedule A (Form 1040), Line 16, and non-corporate taxpayers with taxable bonds acquired after October 22, 1986, but before January 1, 1988, use Form 4952.

• IRS: Instructions for Form 4562 (2025)
• IRS: Publication 946 (2025), How To Depreciate Property

Special Elections, Late Elections, and R&D Transition Rules

Several amortizable categories have specific election statements or transition options.

Under Section 59(e), you can elect an optional write-off period for certain tax preference items so that no Alternative Minimum Tax (AMT) adjustment applies. The optional periods are 3 years for circulation expenditures (Section 173), 60 months for intangible drilling and development costs (Section 263(c)), and 10 years for mining exploration and development costs (Sections 616(a) and 617(a)) as well as eligible research or experimental expenditures.

For domestic research or experimental expenditures paid or incurred in tax years beginning after December 31, 2021, and before January 1, 2025, Section 7.02(2)(f) of Revenue Procedure 2025-28 allows an election to amortize the full remaining unamortized amount in the first tax year beginning after December 31, 2024, or ratably over the 2-tax-year period beginning after that year. You report this amount on Line 43 with the required attached statement.

If an amortization election requires an attached statement (such as pollution control facilities, Section 59(e) optional write-offs, or pre-September 9, 2008 startup costs) and you timely filed your return without making the election, you can still make the election by filing an amended return within 6 months of the due date of the return (excluding extensions). Write 'Filed pursuant to section 301.9100-2' on the amended return.

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• IRS: Instructions for Form 4562 (2025)
• IRS: Publication 946 (2025), How To Depreciate Property