42 CFR § 406.10 - Individual age 65 or over who is entitled to social security or railroad retirement benefits, or who is eligible for social security benefits.
(a) Requirements. An individual is entitled to hospital insurance benefits under section 226 of the Act if he or she has attained aged 65 and is:
(1) Entitled to monthly social security benefits under section 202 of the Social Security Act;
(2) A qualified railroad retirement beneficiary who has been certified as such to the Social Security Administration by the Railroad Retirement Board in accordance with section 7(d) of the Railroad Retirement Act of 1974; or
(3) Effective January 1, 1981, eligible for monthly social security benefits under section 202 of the Act and has filed an application for hospital insurance.
(b) Beginning and end of entitlement.
(1) Entitlement begins with the first day of the first month in which the individual meets the requirements of paragraph (a) of this section.
(2) Entitlement continues until the individual dies or no longer meets the requirements of paragraph (a) of this section. An individual is not entitled to railroad retirement benefits and is neither entitled to, nor eligible for, monthly social security benefits in the month in which he or she dies. However, an individual who meets all other requirements for hospital insurance entitlement is entitled to hospital insurance in the month in which he or she dies if he or she—
(i) Would have been entitled to monthly railroad retirement benefits or social security benefits in that month if he or she had not died; or
(ii) Has filed an application for hospital insurance and would have been eligible for monthly social security benefits in that month if he or she had not died.