Updated September 29, 2026. Quick answer: Box 13 of a Schedule K-1 (Form 1041) has codes A through T and ZZ for credits and credit recapture. The form names every code, and the 2025 instructions say where to report the eleven they describe. Most general business credits also need Form 3800.
Every Box 13 code and its credit name
The instructions read here are the 2025 edition of the IRS Instructions for Schedule K-1 (Form 1041) for a Beneficiary Filing Form 1040 or 1040-SR (Catalog Number 11374Z, dated March 13, 2025), the edition served at the IRS standing PDF address when read on September 29, 2026. They are written for the beneficiary; the fiduciary’s own instructions are in the Instructions for Form 1041. The form’s page 2 names the codes. Codes A and B are covered on their own page.
| Code | Form label | Report on (form’s code list) |
|---|---|---|
| A | Credit for estimated taxes | Form 1040 or 1040-SR, line 26 |
| B | Credit for backup withholding | Form 1040 or 1040-SR, line 25c |
| C | Low-income housing credit | See the beneficiary’s instructions |
| D | Advanced manufacturing production credit | See the beneficiary’s instructions |
| E | Clean electricity production credit | See the beneficiary’s instructions |
| F | Work opportunity credit | See the beneficiary’s instructions |
| G | Credit for small employer health insurance premiums | See the beneficiary’s instructions |
| H | Biofuel producer credit | See the beneficiary’s instructions |
| I | Credit for increasing research activities | See the beneficiary’s instructions |
| J | Renewable electricity production credit | See the beneficiary’s instructions |
| K | Empowerment zone employment credit | See the beneficiary’s instructions |
| L | Clean fuel production credit | See the beneficiary’s instructions |
| M | Orphan drug credit | See the beneficiary’s instructions |
| N | Credit for employer-provided childcare facilities and services | See the beneficiary’s instructions |
| O | Biodiesel and renewable diesel fuels credit | See the beneficiary’s instructions |
| P | Credit to holders of tax credit bonds | See the beneficiary’s instructions |
| Q | Credit for employer differential wage payments | See the beneficiary’s instructions |
| R | Recapture of credits | See the beneficiary’s instructions |
| S | Credit for production from advanced nuclear power facilities | See the beneficiary’s instructions |
| T | Zero-emission nuclear power production credit | See the beneficiary’s instructions |
| ZZ | Other credits | See the beneficiary’s instructions |
Which codes the instructions describe
The instructions say “Codes A through Q, S, T, and ZZ, list all the credits that may be allocated to you as a beneficiary.” Beyond codes A and B, the 2025 instructions have a paragraph for codes C, D, E, H, J, L, O, R, S, T and ZZ only. Codes F, G, I, K, M, N, P and Q are named on the form but have no paragraph in this edition of the instructions. For the eleven that do:
| Code | Credit (form label) | IRS instruction |
|---|---|---|
| C | Low-income housing credit | “Report this amount on Form 8586, line 4.” |
| D | Advanced manufacturing production credit | “Report this amount on Form 7207, Part II, line 7.” |
| E | Clean electricity production credit | “Report this amount on Form 7211, Part II, line 10.” |
| H | Biofuel producer credit | “See the Instructions for Form 6478 for more information.” |
| J | Renewable electricity production credit | “The fiduciary must provide you with a statement showing the amount of credit to report on Form 8835, line 14” |
| L | Clean fuel production credit | “Report this amount on Form 7218, Part II, line 2.” |
| O | Biodiesel and renewable diesel fuels credit | “report this amount on line 10 of Form 8864” |
| R | Recapture of credits | “the fiduciary will provide a statement with the information you need to figure your credit recapture.” |
| S | Credit for production from advanced nuclear power facilities | “Report this amount on Form 7213, Part I, Section 2, line 8.” |
| T | Zero-emission nuclear power production credit | “Report this amount on Form 7213, Part II, Section 2, line 12.” |
| ZZ | Other credits | “Use this code to report the beneficiary’s share of all other credits.” |
General business credits and Form 3800
“Generally, you must file the source credit form along with Form 3800, General Business Credit, to claim the general business credits listed on Schedule K-1 (Form 1041), codes C through O, Q, S, and T, and any general business credits reported using code ZZ.” There is an exception: “if your only source for the credits listed on Form 3800, Part III, is from pass-through entities, you may not be required to complete the source credit form.”
Common mistakes
- Expecting every code to have instructions. Codes F, G, I, K, M, N, P and Q have none in the 2025 instructions.
- Skipping Form 3800 for a general business credit. The instructions say you generally file the source credit form with it.
- Reading a credit code as a refund. Whether a credit reduces your tax depends on your own return.
Related: Schedule K-1 Box 13 Codes A and B: Estimated Tax Credit, Schedule K-1 Box 14 Codes A, B, E and G Explained, and what a K-1 from an estate reports.
Every box and code in one place: the Schedule K-1 (Form 1041) boxes table. What a K-1 from an estate reports overall is on the Schedule K-1 for estates page.
Sources
- IRS, Instructions for Schedule K-1 (Form 1041) for a Beneficiary Filing Form 1040 or 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1041sk1.pdf
- IRS, Schedule K-1 (Form 1041) 2025, Beneficiary’s Share of Income, Deductions, Credits, etc., page 2 code list: https://www.irs.gov/pub/irs-pdf/f1041sk1.pdf
Source: the IRS instructions for the beneficiary who receives Schedule K-1 (Form 1041), and the form’s own code list, read at irs.gov on September 29, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the estate’s or trust’s fiduciary or the IRS is the right place to confirm anything consequential.