---
kind: "section"
citation: "26 U.S.C. § 6233"
title: "26"
title_heading: "Internal Revenue Code"
number: "6233"
heading: "Interest and penalties"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/26/6233"
units:
  - "Subtitle F — Procedure and Administration"
  - "Chapter 63 — Assessment"
  - "Subchapter C — Treatment of Partnerships"
  - "Part III — Procedure"
---

# §6233. Interest and penalties

- (a) **Interest and penalties determined from reviewed year—**
  - (1) **In general—** Except to the extent provided in [section 6226(c)](/usc/26/6226.md?p=c), in the case of a [partnership](/usc/26/7701.md?p=a-2) adjustment for a reviewed year—
    - (A) interest shall be computed under [paragraph (2)](#a-2), and
    - (B) the [partnership](/usc/26/7701.md?p=a-2) shall be liable for any penalty, addition to tax, or additional amount as provided in [paragraph (3)](#a-3).
  - (2) **Determination of amount of interest—** The interest computed under this paragraph with respect to any [partnership](/usc/26/7701.md?p=a-2) adjustment is the interest which would be determined under [chapter 67](/usc/26/chstF/ch67.md) for the period beginning on the day after the return due date for the reviewed year and ending on the return due date for the [adjustment year](/usc/26/7702.md?p=f-11-D) (or, if earlier, the date payment of the imputed [underpayment](/usc/26/6664.md?p=a) is made). Proper adjustments in the amount determined under the preceding sentence shall be made for adjustments required for [partnership](/usc/26/7701.md?p=a-2) [taxable years](/usc/26/7701.md?p=a-23) after the reviewed year and before the [adjustment year](/usc/26/7702.md?p=f-11-D) by reason of such [partnership](/usc/26/7701.md?p=a-2) adjustment.
  - (3) **Penalties—** Any penalty, addition to tax, or additional amount shall be determined at the [partnership](/usc/26/7701.md?p=a-2) level as if such [partnership](/usc/26/7701.md?p=a-2) had been an individual subject to tax under [chapter 1](/usc/26/chstA/ch1.md) for the reviewed year and the imputed [underpayment](/usc/26/6664.md?p=a) were an actual [underpayment](/usc/26/6664.md?p=a) (or understatement) for such year.
- (b) **Interest and penalties with respect to adjustment year return—**
  - (1) **In general—** In the case of any failure to pay an imputed [underpayment](/usc/26/6664.md?p=a) on the date prescribed therefor, the [partnership](/usc/26/7701.md?p=a-2) shall be liable—
    - (A) for interest as determined under [paragraph (2)](#b-2), and
    - (B) for any penalty, addition to tax, or additional amount as determined under [paragraph (3)](#b-3).
  - (2) **Interest—** Interest determined under this paragraph is the interest that would be determined by treating the imputed [underpayment](/usc/26/6664.md?p=a) as an [underpayment](/usc/26/6664.md?p=a) of tax imposed in the [adjustment year](/usc/26/7702.md?p=f-11-D).
  - (3) **Penalties—** Penalties, additions to tax, or additional amounts determined under this paragraph are the penalties, additions to tax, or additional amounts that would be determined—
    - (A) by applying [section 6651(a)(2)](/usc/26/6651.md?p=a-2) to such failure to pay, and
    - (B) by treating the imputed [underpayment](/usc/26/6664.md?p=a) as an [underpayment](/usc/26/6664.md?p=a) of tax for purposes of part II of subchapter A of chapter 68.
- (c) **Deposit to suspend interest—** For rules allowing deposits to suspend running of interest on potential [underpayments](/usc/26/6664.md?p=a), see section 6603.

## Source credit

(Added Pub. L. 114–74, title XI, § 1101(c)(1), Nov. 2, 2015, 129 Stat. 633; amended Pub. L. 115–141, div. U, title II, § 206(i), Mar. 23, 2018, 132 Stat. 1180.)

## Notes

### Editorial Notes

### Prior Provisions

A prior section 6233, added Pub. L. 98–369, div. A, title VII, § 714(p)(1), July 18, 1984, 98 Stat. 964; amended Pub. L. 104–188, title I, § 1307(c)(3)(B), Aug. 20, 1996, 110 Stat. 1782, related to extension to entities filing partnership returns, prior to repeal by Pub. L. 114–74, title XI, § 1101(a), Nov. 2, 2015, 129 Stat. 625.

### Amendments

2018—Subsec. (c). Pub. L. 115–141 added subsec. (c).

### Statutory Notes and Related Subsidiaries

### Effective Date of 2018 Amendment

Amendment by Pub. L. 115–141 effective as if included in section 1101 of Pub. L. 114–74, see section 207 of Pub. L. 115–141, set out as a note under section 6031 of this title.

### Effective Date

Section applicable to returns filed for partnership taxable years beginning after Dec. 31, 2017, with certain exceptions, see section 1101(g) of Pub. L. 114–74, set out as a note under section 6221 of this title.