K-1 box 20 codes: every Schedule K-1 (Form 1065) code from A to ZZ
K-1 box 20 codes are the letter codes a partnership uses on Schedule K-1 (Form 1065) to report other information a partner needs, from investment income (code A) and section 199A information (code Z) to section 751 gain (code AB). The 2025 list runs from A to AZ, plus ZZ for other items.
“If the partnership made a noncash charitable contribution, your share of the charitable contribution equal to the amount of the partnership’s adjusted basis in the property is limited to your outside basis and is reported here.” IRS, Partner’s Instructions for Schedule K-1 (Form 1065) (2025)
What does K-1 box 20 report?
K-1 box 20 reports other information a partner needs to complete their return that isn't a plain income or deduction amount. According to the Partner's Instructions for Schedule K-1 (Form 1065) (2025), box 20 carries inputs for partner-level calculations: Form 4952 investment items, Form 8990 items, section 199A information, credit recapture, interest charges and the split of gain on the sale of an interest.
The 2025 list runs from code A to code AZ, with codes BA through BD reserved and code ZZ for anything else. The meaning of a code depends on the year of the form, so the reviewer reads the code against the instructions for the K-1's tax year. For 2025, code AH is noncash charitable contributions and code ZZ includes the information a partner needs to make the new section 1062 election to pay tax on a sale of qualified farmland property to a qualified farmer in four annual installments. Most box 20 codes come with an attached statement.
What does each box 20 code mean and where does it go?
Every 2025 box 20 code is listed below with its meaning from the List of Codes in the 2025 partner's instructions and where an individual partner uses it. Codes marked information only don't go on a line by themselves; they support a calculation or repeat an amount already reported elsewhere on the K-1.
| Code | Meaning (2025) | Where it is used |
|---|---|---|
| A | Investment income | Form 4952, line 4a |
| B | Investment expenses | Form 4952, line 5 |
| C | Fuel tax credit information | Form 4136 |
| D | Qualified rehabilitation expenditures (other than rental real estate) | Form 3468, combined with box 15, code E |
| E | Basis of energy property | Form 3468, Part VI |
| F | Recapture of low-income housing credit (section 42(j)(5) partnerships) | Form 8611 |
| G | Recapture of low-income housing credit (other partnerships) | Form 8611 |
| H | Recapture of investment credit | Form 4255 |
| I | Recapture of other credits | Form 8874, Form 8882 or the section named on the statement |
| J | Look-back interest, completed long-term contracts | Form 8697 |
| K | Look-back interest, income forecast method | Form 8866 |
| L | Dispositions of property with section 179 deductions | Form 4797 (Form 4684 or 6252 if a casualty or installment sale) |
| M | Recapture of section 179 deduction | Recapture figured under the Instructions for Form 4797 |
| N | Business interest expense (BIE) | Information only; separate loss class for basis |
| O | Section 453(l)(3) information | Schedule 2 (Form 1040), Part II, line 14 |
| P | Section 453A(c) information | Interest on deferred tax, on the other taxes line |
| Q | Section 1260(b) information | Schedule 2 (Form 1040), Part II, line 17z |
| R | Interest allocable to production expenditures | Capitalized under section 263A |
| S | Capital construction fund (CCF) nonqualified withdrawals | Schedule 2 (Form 1040), Part II, line 17z |
| T | Depletion information, oil and gas | Partner's own depletion calculation |
| U | Section 743(b) basis adjustment | Information, by asset grouping |
| V | Unrelated business taxable income | Tax-exempt partners' UBTI |
| W | Precontribution gain (loss) | Form 8949 and Schedule D, or Form 4797 |
| X | Payment obligations including guarantees and deficit obligations (DROs) | Information tied to item K3 |
| Y | Net investment income (NII) | Form 8960 |
| Z | Section 199A information | Form 8995 or Form 8995-A; see code Z |
| AA | Section 704(c) information | Information; already in other boxes |
| AB | Section 751 gain (loss) | Ordinary gain on sale of the interest; Form 4797 |
| AC | Section 1(h)(5) collectibles gain | Collectibles gain on sale of the interest; Schedule D |
| AD | Section 1(h)(6) unrecaptured section 1250 gain | Unrecaptured Section 1250 Gain Worksheet, line 10 |
| AE | Excess taxable income | Form 8990, Schedule A, line 43, column (f) |
| AF | Excess business interest income | Form 8990, Schedule A, line 43, column (g) |
| AG | Gross receipts for section 448(c) | Partner's gross receipts test |
| AH | Noncash charitable contributions | Basis limit under section 704(d)(3); FMV over basis |
| AI | Interest and tax on deferred compensation to partners | Schedule 2 (Form 1040), Part II, line 17h |
| AJ | Excess business loss limitation | Form 461 |
| AK | Gain from mark-to-market election | Section 475(f) ordinary gain (loss) |
| AL | Section 721(c) partnership | Remedial items; Schedule G (Form 8865) amounts |
| AM | Section 1061 information | Capital gain on an applicable partnership interest |
| AN | Farming and fishing business | Section 1301 income averaging |
| AO | PTP information | Partner that is a PTP, 90% qualifying income test |
| AP | Inversion gain | Information; floor on taxable income under section 7874 |
| AQ | Conservation reserve program payments | Schedule SE, line 1b |
| AR | IRA disclosure | Form 990-T |
| AS | Qualifying advanced coal project property and qualifying gasification project property | Form 3468, Part II |
| AT | Qualifying advanced energy project property | Form 3468, Part III |
| AU | Advanced manufacturing investment property | Form 3468, Part IV |
| AV | Clean electricity investment property | Form 3468, Part V |
| AW | Reportable transactions | Form 8886 |
| AX | Corporate alternative minimum tax (CAMT) | Corporate partner's adjusted financial statement income |
| AY | Foreign partners, Form 8990, Schedule A | Form 8990, Schedule A |
| AZ | Reimbursement of preformation expenditures | Disguised sale exception, Treas. Reg. 1.707-4(d) |
| BA to BD | Reserved for future use | None |
| ZZ | Other | Per the statement, including Form 1062 for a section 1062 election |
Codes A and B work with box 13, code H: Form 4952 limits investment interest expense to net investment income, and the partner adds investment income and expenses from other sources. Code AQ matters only for partners who received social security retirement or disability benefits, who exclude those payments from self-employment tax on Schedule SE, line 1b. Code AE and code AF go on Form 8990 only if the partner is required to file it, according to the instructions for those codes.
Which box 20 codes repeat amounts reported elsewhere?
Several box 20 codes repeat amounts already included in other K-1 boxes, and the 2025 partner's instructions say so directly. Reporting them again double counts income or deductions, and a reviewer comparing the K-1 face with Schedule E or Form 4797 can catch the duplicate by reading each statement before entering anything.
- Code N: deductible business interest expense already deducted on another line, reported only so the partner can treat it as a separate loss class for the basis limit.
- Code AA: section 704(c) items included elsewhere on the K-1.
- Code AI: interest and additional tax under section 409A on income that is already in box 4a or 4b.
- Code AP: inversion gain already included in income elsewhere.
- Codes AB, AC and AD: also reported on Form 8308, Part IV, but reported only once on the partner's return.
Codes AC and AD apply to the sale of the partnership interest itself. Collectibles gain and unrecaptured section 1250 gain from assets the partnership sold flow through boxes 9b and 9c instead. Code AH also needs care: the partner's share of a noncash contribution equal to the partnership's adjusted basis in the property is limited to the partner's outside basis under section 704(d)(3), so it belongs on the partner basis worksheet before the deduction is claimed.
What does a box 20 sale-of-interest calculation look like?
For example, Priya sells her entire partnership interest in 2025 for an amount realized of $250,000, including her share of partnership liabilities she is relieved of. Her outside basis at the sale is $150,000, and she has held the interest for more than three years. Her final K-1 reports $30,000 of section 751 gain under box 20, code AB, $25,000 of unrecaptured section 1250 gain under code AD, and no collectibles gain under code AC.
| Step | Where it goes | Amount |
|---|---|---|
| Amount realized | Sale records | $250,000 |
| Outside basis at sale | Basis worksheet | $150,000 |
| Total gain on the sale | $100,000 | |
| Ordinary gain (box 20, code AB) | Form 4797 | $30,000 |
| Capital gain (total gain minus code AB) | Form 8949 and Schedule D | $70,000 |
| Of which unrecaptured section 1250 gain (code AD) | Worksheet, line 10 | $25,000 |
| Long-term capital gain outside codes AC and AD | Schedule D | $45,000 |
The Instructions for Form 8308 (Rev. November 2025) say the deemed sale section 751(a) gain is reported on Form 4797 and the capital gain on Form 8949. The $25,000 of code AD gain is part of the $70,000 capital gain, not an addition to it, and goes on line 10 of the Unrecaptured Section 1250 Gain Worksheet as the partner instructions direct for a sale of a partnership interest. Form 8308 covers the partnership's side.
What do reviewers check on K-1 box 20?
A reviewer working through K-1 box 20 confirms six items, each tied to the 2025 partner's instructions. Every attached statement needs to be in the file, because most box 20 codes show STMT instead of an amount. The prior-year return matters for code A and B (a Form 4952 carryforward), and for any year the partner sold part or all of an interest, Form 8308 from the partnership should be compared against codes AB, AC and AD. Codes that relate to credits, such as D, E and AS through AV, also need the matching box 15 codes and the credit forms they feed. A code the reviewer doesn't recognize should be read against the 2025 List of Codes, not a prior year's list.
Every line checked against the documents the client sent
Filed reads the partner's K-1, every box 20 statement, Form 8308 and the prior-year return, then checks each box 20 code against the line it feeds. Anything that doesn't tie comes back as a review item with a citation to the source.
Book a demoSchedule E line 28 has a separate $12,400 interest expense row matching box 20 code N, but the code N statement shows that BIE is already inside box 1. Confirm whether the separate row should be removed.
Common questions
What is K-1 box 20 code AH?
K-1 box 20 code AH is noncash charitable contributions on the 2025 Schedule K-1 (Form 1065). It reports the partner's share of a noncash contribution equal to the partnership's adjusted basis in the property, which is limited to outside basis under section 704(d)(3), plus the share of fair market value above basis for noncash and capital gain property.
Where does K-1 box 20 code A go?
K-1 box 20 code A, investment income, goes on Form 4952, Part II, line 4a, according to the 2025 partner's instructions. Code B, investment expenses, goes on line 5. Together with box 13, code H investment interest expense and investment items from other sources, they decide how much investment interest is deductible this year.
What is K-1 box 20 code ZZ?
K-1 box 20 code ZZ is the catch-all for any other information a partner needs that isn't shown elsewhere on Schedule K-1. For 2025 it includes the information needed for a section 1062 election on a sale of qualified farmland property to a qualified farmer, which requires Form 1062 and Schedule A (Form 1062).