26 USC § 6665 - Applicable rules

---
identifier: "/us/usc/t26/s6665"
source: "usc"
legal_status: "official_prima_facie"
title: "26 USC § 6665 - Applicable rules"
title_number: 26
title_name: "INTERNAL REVENUE CODE"
section_number: "6665"
section_name: "Applicable rules"
chapter_number: 68
chapter_name: "ADDITIONS TO THE TAX, ADDITIONAL AMOUNTS, AND ASSESSABLE PENALTIES"
subchapter_number: "A"
subchapter_name: "Additions to the Tax and Additional Amounts"
part_number: "III"
part_name: "APPLICABLE RULES"
positive_law: false
currency: "119-84"
last_updated: "2026-04-17"
format_version: "1.1.0"
generator: "[email protected]"
source_credit: "(Added Pub. L. 101–239, title VII, § 7721(a), Dec. 19, 1989, 103 Stat. 2399.)"
---


# § 6665. Applicable rules

**(a)** **Additions treated as tax** Except as otherwise provided in this title—

**(1)** the additions to the tax, additional amounts, and penalties provided by this chapter shall be paid upon notice and demand and shall be assessed, collected, and paid in the same manner as taxes; and

**(2)** any reference in this title to “tax” imposed by this title shall be deemed also to refer to the additions to the tax, additional amounts, and penalties provided by this chapter.

**(b)** **Procedure for assessing certain additions to tax** For purposes of subchapter B of chapter 63 (relating to deficiency procedures for income, estate, gift, and certain excise taxes), subsection (a) shall not apply to any addition to tax under section 6651, 6654, or 6655; except that it shall apply—

**(1)** in the case of an addition described in section 6651, to that portion of such addition which is attributable to a deficiency in tax described in section 6211; or

**(2)** to an addition described in section 6654 or 6655, if no return is filed for the taxable year.

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**Source Credit**: (Added Pub. L. 101–239, title VII, § 7721(a), Dec. 19, 1989, 103 Stat. 2399.)

## Statutory Notes and Related Subsidiaries

### Effective Date

Section applicable to returns the due date for which (determined without regard to extensions) is after , see , set out as an Effective Date of 1989 Amendment note under .