§ 404.120 How we determine currently insured status.
(a) What the period is for determining currently insured status. You are currently insured if you have at least 6 quarters of coverage (QCs) during the 13-quarter period ending with the quarter in which you—
(1) Die;
(2) Most recently became entitled to disability insurance benefits; or
(3) Became entitled to old-age insurance benefits.
(b) What quarters are not counted as part of the 13-quarter period. We do not count as part of the 13-quarter period any quarter all or part of which is included in a period of disability established for you, except that the first and last quarters of the period of disability may be counted if they are QCs (see § 404.146(d)).