Updated October 18, 2026. Quick answer: Lines 15a to 17 of Form 1041 finish the deductions section. Line 15a is a catch-all for allowable deductions not reported elsewhere, listed on your own attached statement. Line 15b is the net operating loss deduction, line 16 adds lines 10 through 15b, and line 17 subtracts that total from total income to give adjusted total income.
What lines 15a to 17 do
The form’s captions read “Other deductions (attach schedule).” for line 15a, “Net operating loss deduction.” for line 15b, “Add lines 10 through 15b” for line 16 and “Adjusted total income or (loss). Subtract line 16 from line 9” for line 17.
Earlier deduction lines are on the lines 10 to 12 and lines 13 and 14 pages. Line 9 comes from the income section, explained on the lines 4 to 9 page.
Line 15a: what to enter and what to attach
The instructions say “Attach your own statement, listing by type and amount all allowable deductions that aren’t deductible elsewhere on Form 1041.”
They describe allowable deductions as “other costs allowable under section 67(e) paid or incurred in connection with the administration of the estate or trust that would not have been incurred if the property were not held in the estate or trust.”
The test they give: “it must be determined whether the cost would be “commonly or customarily” incurred by a hypothetical individual owning the same property.” And then: “If the cost would be deductible by a hypothetical individual, it is not deductible by the estate or nongrantor trust.”
Costs the instructions say do not belong here
On funeral and medical bills the instructions say “Don’t deduct medical or funeral expenses on Form 1041.” and “Funeral expenses are deductible only on Form 706.” The funeral costs and the estate page covers that cost.
On ownership costs: “Ownership costs are costs that are chargeable to or incurred by an owner of property simply by reason of being the owner of the property.” On appraisals, “Appraisal fees incurred to determine the FMV of assets as of the decedent’s date of death” are on the deductible side, while “The cost of appraisals for other purposes (for example, insurance) is commonly or customarily incurred by individuals and is not an allowable deduction.”
On investment advice: “Fees for investment advice, including any related services that would be provided to any individual investor as part of an investment advisory fee, are incurred commonly or customarily by a hypothetical individual investor and are not deductible.”
Items the instructions list for line 15a
Under the heading “Other Deductions Reported on Line 15a” the instructions include “Use Form 4684, Casualties and Thefts, to figure any deductible casualty and theft losses.” They also say “Don’t report the beneficiary’s apportioned share of depreciation, depletion, and amortization on line 15a.” The beneficiary’s share goes elsewhere: “Report the beneficiary’s apportioned share of deductions in box 9 of Schedule K-1 (Form 1041).” See Schedule K-1 for the beneficiary side.
Line 15b: net operating loss deduction
The instructions are short: “An estate or trust is allowed an NOLD under section 172.” and “If you claim an NOLD for the estate or trust, figure the deduction on a separate sheet and attach it to the return.”
Where the number comes from
Line 15a comes from your own attached statement, built from the estate’s or trust’s bills and invoices, sorted by type and amount. Line 15b comes from the separate sheet you attach. Line 16 is the sum of lines 10 through 15b, and line 17 is line 9 less line 16. Nothing on these lines is copied from a table.
Where it goes next
Line 17 feeds two places. On Schedule B the instructions say “Generally, enter on Schedule B, line 1, the amount from line 17 on page 1 of Form 1041.” The Schedule B lines 1 to 8 page covers that line. On page 1, line 23 reads “Taxable income. Subtract line 22 from line 17.” The lines 18 to 22 and lines 23 to 30 pages continue the walk down the form.
Edition and line numbers
This page reads Form 1041 (2025) and the 2025 Instructions for Form 1041 and Schedules A, B, G, J, and K-1. Those are the current files irs.gov served on 2026-10-18, byte-identical to the archived copies. The form reads “For calendar year 2025 or fiscal year beginning” and the instructions carry the title “Instructions for Form 1041 (2025)”. Check the year printed on your own Form 1041 and use the line numbers on that year’s form.
Common mistakes
- Deducting funeral or medical bills on the income tax return. The instructions say “Don’t deduct medical or funeral expenses on Form 1041.”
- Listing a cost an individual would also bear. The instructions say “If the cost would be deductible by a hypothetical individual, it is not deductible by the estate or nongrantor trust.”
- Skipping the statement for line 15a. The instructions say “Attach your own statement, listing by type and amount all allowable deductions that aren’t deductible elsewhere on Form 1041.”
Related: Form 1041, funeral costs and the estate, Schedule K-1 for estates, and distribution deduction and DNI.
Sources
- Instructions for Form 1041 and Schedules A, B, G, J, and K-1 (2025), U.S. Income Tax Return for Estates and Trusts: https://www.irs.gov/pub/irs-pdf/i1041.pdf
- Form 1041 (2025), U.S. Income Tax Return for Estates and Trusts: https://www.irs.gov/pub/irs-pdf/f1041.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.