26 CFR § 1.7701-1 - Definitions; spouse, husband and wife, husband, wife, marriage.

---
identifier: "/us/cfr/t26/s1.7701-1"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "26 CFR § 1.7701-1 - Definitions; spouse, husband and wife, husband, wife, marriage."
title_number: 26
title_name: "Internal Revenue"
section_number: "1.7701-1"
section_name: "Definitions; spouse, husband and wife, husband, wife, marriage."
chapter_name: "INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY"
subchapter_number: "A"
subchapter_name: "INCOME TAX"
part_number: "1"
part_name: "INCOME TAXES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "26 U.S.C. 7805, unless otherwise noted."
regulatory_source: "T.D. 6500, 25 FR 11402, Nov. 26, 1960; 25 FR 14021, Dec. 21, 1960; T.D. 9989, 89 FR 17606, Mar. 11, 2024, unless otherwise noted."
cfr_part: "1"
---


# 1.7701-1 Definitions; spouse, husband and wife, husband, wife, marriage.

(a) *In general.* For the definition of the terms spouse, husband and wife, husband, wife, and marriage, see § 301.7701-18 of this chapter.

(b) *Applicability date.* The rules of this section apply to taxable years ending on or after September 2, 2016.

[T.D. 9785, 81 FR 60616, Sept. 2, 2016]