42 CFR § 406.3 - Definitions.

---
identifier: "/us/cfr/t42/s406.3"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "42 CFR § 406.3 - Definitions."
title_number: 42
title_name: "Public Health"
section_number: "406.3"
section_name: "Definitions."
chapter_name: "CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "MEDICARE PROGRAM"
part_number: "406"
part_name: "HOSPITAL INSURANCE ELIGIBILITY AND ENTITLEMENT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 1302, 1395i-2, 1395i-2a, 1395p, 1395q and 1395hh."
regulatory_source: "48 FR 12536, Mar. 25, 1983, unless otherwise noted. Redesignated at 51 FR 41338, Nov. 14, 1986."
cfr_part: "406"
---


# 406.3 Definitions.

*First month of eligibility* means the first month in which an individual meets all the requirements for entitlement to hospital insurance except application or enrollment if that is required.

*First month of entitlement* means the first month for which the individual meets all the requirements for entitlement to Part A benefits.

*Insured individual* means an individual who has the number of quarters of coverage required for monthly social security benefits.

*Quarter of coverage* means a calendar quarter that is counted toward the number of covered quarters required to make the individual eligible for monthly social security benefits. A quarter is counted if during that quarter (or that calendar year) the individual earned a required minimum amount of money. (For details, see 20 CFR part 404, subpart B.)