26 USC § 6204 - Supplemental assessments

---
identifier: "/us/usc/t26/s6204"
source: "usc"
legal_status: "official_prima_facie"
title: "26 USC § 6204 - Supplemental assessments"
title_number: 26
title_name: "INTERNAL REVENUE CODE"
section_number: "6204"
section_name: "Supplemental assessments"
chapter_number: 63
chapter_name: "ASSESSMENT"
subchapter_number: "A"
subchapter_name: "In General"
positive_law: false
currency: "119-84"
last_updated: "2026-04-17"
format_version: "1.1.0"
generator: "[email protected]"
source_credit: "(Aug. 16, 1954, ch. 736, 68A Stat. 768; Pub. L. 93–406, title II, § 1016(a)(27), Sept. 2, 1974, 88 Stat. 932; Pub. L. 94–455, title XIX, § 1906(b)(13)(A), Oct. 4, 1976, 90 Stat. 1834.)"
---


# § 6204. Supplemental assessments

**(a)** **General rule** The Secretary may, at any time within the period prescribed for assessment, make a supplemental assessment whenever it is ascertained that any assessment is imperfect or incomplete in any material respect.

**(b)** **Restrictions on assessment** For restrictions on assessment of deficiencies in income, estate, gift, and certain excise taxes, see section 6213.

---

**Source Credit**: (Aug. 16, 1954, ch. 736, 68A Stat. 768; Pub. L. 93–406, title II, § 1016(a)(27), Sept. 2, 1974, 88 Stat. 932; Pub. L. 94–455, title XIX, § 1906(b)(13)(A), Oct. 4, 1976, 90 Stat. 1834.)

## Editorial Notes

### Amendments

1976—Subsec. (a).  struck out “or his delegate” after “Secretary”.

1974—Subsec. (b).  substituted “gift, and certain excise taxes” for “and gift taxes”.

## Statutory Notes and Related Subsidiaries

### Effective Date of 1974 Amendment

Amendment by  applicable, except as otherwise provided in section 1017(c) through (i) of , for plan years beginning after , and, in the case of plans in existence on , amendment by  applicable for plan years beginning after , see , set out as an Effective Date; Transitional Rules note under .