Updated October 16, 2026. Quick answer: Box 13 of Schedule K-1 (Form 1065) lists a partner’s other deductions, one code at a time. Codes A to G are charitable gifts with different AGI limits and go to Schedule A, code H is investment interest for Form 4952, and the rest go to Schedule E, Schedule 1, Form 8990 or other forms as the 2025 instructions say.
What box 13 reports
On the form, line 13 of Part III is labelled “Other deductions”. Each deduction has its own code, and the code decides the form. This page covers the partner’s side of a K-1 you received; it does not cover how the partnership files its own return. Every other box is set out on the Schedule K-1 (Form 1065) boxes overview.
The instructions list four limits and put them in a fixed order: “These limitations and the order in which you must apply them are as follows: the basis limitations, the at-risk limitations, the passive activity limitations, and the excess business loss limitations.” The amounts printed in Part III are before any of them. “The amounts shown in boxes 1 through 21 reflect your share of income, loss, deductions, credits, and other items from partnership business or rental activities without reference to limitations on losses or adjustments that may be required of you”.
Codes A to G: charitable contributions
The instructions group these codes under one heading: “The partnership will give you a statement that shows charitable contributions subject to the 100%, 60%, 50%, 30%, and 20% AGI limitations.” “If your contributions are subject to more than one of the AGI limitations, see Worksheet 2 in Pub. 526.”
| Code | Contribution type, as printed | Where it goes |
|---|---|---|
| A | “Cash contributions (60%)” | “Report this amount, subject to the 60% AGI limitation, on Schedule A (Form 1040), line 11.” |
| B | “Cash contributions (30%)” | “Report this amount, subject to the 30% AGI limitation, on Schedule A (Form 1040), line 11.” |
| C | “Noncash contributions (50%)” | “Report this amount, subject to the 50% AGI limitation, on Schedule A (Form 1040), line 12.” |
| D | “Noncash contributions (30%)” | “Report this amount, subject to the 30% AGI limitation, on Schedule A (Form 1040), line 12.” |
| E | “Capital gain property to a 50% organization (30%)” | “Report this amount, subject to the 30% AGI limitation, on Schedule A (Form 1040), line 12.” |
| F | “Capital gain property (20%)” | “Report this amount, subject to the 20% AGI limitation, on Schedule A (Form 1040), line 12.” |
| G | “Contributions (100%)” | For qualified conservation contributions of property used in agriculture or livestock production: “If you’re a farmer or rancher, you qualify for a 100% AGI limitation for this contribution. Otherwise, your deduction for this contribution is subject to a 50% AGI limitation. Report this amount on Schedule A (Form 1040), line 12.” |
Charitable gifts stay out of the passive loss calculation. “Charitable contribution deductions aren’t taken into account in figuring your passive activity loss for the year. Don’t include them on Form 8582.” The destination for these codes is Schedule A (Form 1040).
Noncash gifts and Form 8283
For code C: “If property other than cash is contributed, and if the claimed deduction for one item or group of similar items of property exceeds $500, the partnership must give you a copy of Form 8283, Noncash Charitable Contributions, to attach to your tax return.” “Don’t deduct the amount shown on Form 8283. It’s the partnership’s contribution.”
Food inventory has its own limit and is separate from code C. “Your deduction for food inventory contributions made during 2025 can’t exceed 15% of your aggregate net income for the tax year from the business activities from which the food inventory contribution was made”. “Amounts that exceed the 15% limitation may be carried over for up to 5 years.”
Code H: investment interest expense
Code H goes to Form 4952, which is explained on the Form 4952 page. “If the partnership has investment income or other investment expense, it’ll report your share of these items in box 20 of Schedule K-1 using codes A and B.” “Include investment income and expenses from other sources to figure how much of your total investment interest is deductible.”
Every other box 13 code
The table gives the destination for the remaining codes, as printed. Some letters are not in use: “Code Q. Reserved for future use.” “Codes T through U. Reserved for future use.” “Codes AF through AJ. Reserved for future use.”
| Code | What it is, as printed | Where it goes |
|---|---|---|
| H | “Investment interest expense.” | “Include this amount on Form 4952, line 1.” |
| I | Deductions for royalty income | “Include deductions allocable to royalties on Schedule E (Form 1040), line 19.” |
| J | “Section 59(e)(2) expenditures.” | “Make the election on Form 4562.” |
| K | “Excess business interest expense (EBIE).” | “If the partnership reports EBIE to the partner, the partner is required to file Form 8990.” |
| L | Deductions for portfolio income (other) | “Generally, you should report these amounts on Schedule A (Form 1040), line 16.” |
| M | “Amounts paid for medical insurance.” | “On Schedule 1 (Form 1040), line 17, you may be allowed to deduct such amounts, even if you don’t itemize deductions.” |
| N | “Educational assistance benefits.” | “Use this amount to deduct your educational assistance benefits on a separate line of Schedule E (Form 1040), line 28, up to the $5,250 limitation.” |
| O | “Dependent care benefits.” | “You must use Form 2441, Part III, to figure the amount, if any, of the benefits you may exclude from your income.” |
| P | “Preproductive period expenses.” | “You may be able to deduct these expenses currently or you may need to capitalize them under section 263A.” |
| R | “Pensions and IRAs.” | “Enter payments made to a qualified plan, SEP, or SIMPLE IRA plan on Schedule 1 (Form 1040), line 16.” |
| S | “Reforestation expense deduction.” | “The expense deduction is limited to $10,000 ($5,000 if married filing separately) for each qualified timber property” |
| V | “The partnership will use this code to report the net negative income adjustment resulting from all section 743(b) basis adjustments.” | Box 20, code U, carries the adjustment net of cost recovery |
| W | “Soil and water conservation.” | “a portion of which may be deductible on Schedule F (Form 1040) by taxpayers engaged in the business of farming” |
| X | “Qualified film, television, theatrical, and sound recording production expenses.” | “See section 181(a)(2) for limitations on the amount you’re allowed to deduct.” |
| Y | “Expenditures for removal of barriers.” | “The deductions are limited by section 190(c) to $15,000 per year from all sources.” |
| Z | “Itemized deductions.” | “The partnership will provide a statement outlining itemized deductions that Form 1040 or 1040-SR filers report on Schedule A (Form 1040).” |
| AA | “Contributions to a capital construction fund (CCF).” | “The deduction for a CCF investment isn’t taken on Schedule E (Form 1040). Instead, you subtract the deduction from the amount that would normally be entered as taxable income on Form 1040 or 1040-SR, line 15.” |
| AB | “Penalty on early withdrawal of savings.” | “Report this amount on Schedule 1 (Form 1040), Part II, line 18.” |
| AC | “Interest expense allocated to debt-financed distributions.” | “The manner in which you report such interest expense depends on your use of the distributed debt proceeds.” |
| AD | “Interest expense on working interest in oil or gas.” | “If you materially participated in the activity, report the interest on Schedule E (Form 1040), line 28.” If you didn’t materially participate in the oil or gas activity, the instructions say this interest is investment interest expense and should be reported on Form 4952. |
| AE | “Deductions” for portfolio income | “For taxpayers other than individuals, deduct amounts that are clearly and directly allocable to portfolio income” |
| ZZ | “Any other information you may need to file your tax return.” | As the K-1 statement directs |
Code K: excess business interest expense
Code K carries a basis rule as well as a form. “For tax years beginning after 2017, the partner’s basis in its partnership interest at the end of the tax year is reduced (but not below zero) by the amount of excess business interest allocated to the partner for the tax year”, “even if the partner isn’t allowed a deduction for the allocated excess business interest in the year of the basis reduction.” “If the partner disposes of a partnership interest in which the basis has been reduced before all of the allocated excess business interest was used, the partner increases its basis immediately before the sale for the amount not yet deducted.”
Codes I and J: passive rules and the Schedule E column
Code I deductions are kept out of Form 8582, and the instructions say the same for code L and for the charitable codes A to G. For code I, “These deductions aren’t taken into account in figuring your passive activity loss for the year. Don’t enter them on Form 8582.” Code J works differently. “Whether you deduct the expenditures or elect to amortize them, report the amount on a separate line of column (i) of Schedule E (Form 1040), line 28, if you materially participated in the partnership activity.” Schedule E is covered on its own page.
Basis and at-risk limits on box 13 losses
Basis is the partner’s own job to track. “Any losses and deductions not allowed can be carried forward.” “It’s the partner’s responsibility to track and maintain the information necessary to figure their adjusted basis in the partnership (also known as outside basis).”
For the at-risk step, “you’ll have to complete Form 6198, At-Risk Limitations, to figure your allowable loss for the activity.” Form 6198 is covered on the Form 6198 page.
Some items carry their own limit first. “Other limitations may apply to specific deductions (for example, the section 179 expense deduction). Generally, specific limitations apply before the at-risk and passive loss limitations.”
Which revision applies
The edition read for this page is the 2025 Partner’s Instructions for Schedule K-1 (Form 1065) and the 2025 Schedule K-1 (Form 1065) itself, which are the revisions irs.gov served when they were read on 2026-10-16. Check the revision printed on the Schedule K-1 you received and the matching instructions, because a later edition can change the box layout, the column letters and the reporting lines.
Common mistakes
- Putting every charitable code on one Schedule A line. The instructions send codes A and B to line 11 and codes C to G to line 12, each subject to its own AGI limitation.
- Running charitable gifts through Form 8582. The instructions say charitable contribution deductions are not taken into account in figuring the passive activity loss and are not included on Form 8582.
- Missing the code K basis cut. The instructions reduce the partner’s basis by the excess business interest allocated for the year, even when the partner is not allowed to deduct it that year.
Related: Schedule A (Form 1040) itemized deductions, Form 4952 investment interest expense, Schedule E (Form 1040), Form 8582 passive activity loss limits, and Schedule K-1 (Form 1065) boxes explained.
Sources
- 2025 Partner’s Instructions for Schedule K-1 (Form 1065): https://www.irs.gov/pub/irs-pdf/i1065sk1.pdf
- Schedule K-1 (Form 1065) (2025), Partner’s Share of Income, Deductions, Credits, etc.: https://www.irs.gov/pub/irs-pdf/f1065sk1.pdf
Read from the IRS documents linked above on October 16, 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.