Updated October 18, 2026. Quick answer: Part VI is for amortization, the deduction of certain capital costs over a fixed period. Line 42 lists costs whose amortization begins this year, line 43 is amortization of costs that began earlier, and line 44 is the total. The total is reported on the other deductions or other expenses line of your return.
What Part VI asks for
The instructions open Part VI with “Each year, you can deduct part of certain capital costs over a fixed period.” The captions are “Amortization of costs that begins during your 2025 tax year (see instructions):”, “Amortization of costs that began before your 2025 tax year” and a total line. The instructions add a limit: “If you amortize property, the part you amortize does not qualify for the section 179 expense deduction or for depreciation.” The earlier parts are at lines 14 to 20, and this page is part of the Form 4562 walk-through.
Line 42: costs that begin this year
The instructions say “Complete line 42 only for those costs you amortize for which the amortization period begins during your tax year beginning in 2025.” For column (a) the instruction is “Describe the costs you are amortizing.” and the list of what you can amortize includes business startup costs and organizational costs. For example, the list shows “Business startup costs (section 195).” and “Organizational costs for a corporation (section 248).” The instructions send you to the Code section and regulations for each cost’s rules.
Line 42 columns (b) to (f)
Column (b) says “Enter the date the amortization period begins under the applicable Code section.” Column (c) says “Enter the total amount you are amortizing.” Column (d) says “Enter the Code section under which you amortize the costs.” For column (f) the instructions give two ways: “Dividing the amount in column (c) by the number of months over which the costs are to be amortized and multiplying the result by the number of months in the amortization period included in your tax year beginning in 2025”, or “Multiplying the amount in column (c) by the percentage in column (e).”.
A computed illustration, not an IRS example, of the first method: if column (c) were $12,000 and the months over which the costs are amortized were 60, then $12,000 divided by 60 is a computed $200 a month. If 6 months fell in the tax year, then $200 times 6 is a computed $1,200.
Line 43: costs that began earlier
The instructions say “If you are reporting the amortization of costs (other than research or experimental expenditures) that began before your 2025 tax year and you are not required to file Form 4562 for any other reason, do not file Form 4562.” In that case “Report the amortization directly on the “Other Deductions” or “Other Expenses” line of your return.” If you do report on line 43 the instructions say “Attach a statement that shows (a) a description of the costs; (b) the date amortization began; (c) the amortizable amount; (d) the applicable Code section; (e) the amortization period; (f) the accumulated amortization; and (g) the amortization amount for this year.”
Line 44: the total
The caption is “Total. Add amounts in column (f). See the instructions for where to report”. The instructions say “Report the total amortization, including amortization for research and experimental expenditures paid or incurred in 2025 and prior years and the allowable portion of forestation or reforestation amortization, on the applicable “Other Deductions” or “Other Expenses” line of your return.” Partnerships and S corporations report some items separately; for those, the instructions refer to the Schedule K instructions.
Where the number comes from
Line 42 comes from your records of each cost, its start date and its amortization period under the Code section you cite. Line 43 comes from earlier years’ schedules, and line 44 adds the column (f) amounts.
Where it goes next
The instructions send the line 44 total to the return’s other deductions or other expenses line, as quoted above. For a sole proprietor that line is on the business schedule, explained at Schedule C, and the Schedule C lines 12 and 13 page covers depletion and depreciation.
Edition and line numbers
This page reads the 2025 Form 4562, Depreciation and Amortization, and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are the files for the tax year 2025 return, filed in 2026. The form’s own header says “Attach to your tax return.” Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently.
Common mistakes
- Also depreciating or expensing an amortized cost. The instructions say “If you amortize property, the part you amortize does not qualify for the section 179 expense deduction or for depreciation.”
- Filing Form 4562 only for older amortization. The instructions say “If you are reporting the amortization of costs (other than research or experimental expenditures) that began before your 2025 tax year and you are not required to file Form 4562 for any other reason, do not file Form 4562.”
- Leaving the total on Form 4562 only. The instructions say “Report the total amortization, including amortization for research and experimental expenditures paid or incurred in 2025 and prior years and the allowable portion of forestation or reforestation amortization, on the applicable “Other Deductions” or “Other Expenses” line of your return.”
Related: Form 4562, Schedule C, Schedule C lines 12 and 13, and Schedule 1 lines 3 to 6.
Sources
- Instructions for Form 4562, Depreciation and Amortization (2025): https://www.irs.gov/pub/irs-pdf/i4562.pdf
- Form 4562, Depreciation and Amortization (2025): https://www.irs.gov/pub/irs-pdf/f4562.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.