[{"bornBefore":"1949-07-01","applicableAge":70.5},{"bornFrom":"1949-07-01","bornBefore":"1951-01-01","applicableAge":72},{"bornFrom":"1951-01-01","bornBefore":"1959-01-01","applicableAge":73},{"bornFrom":"1959-01-01","bornBefore":"1960-01-01","applicableAge":null,"proposedApplicableAge":73,"status":"reserved in 26 CFR 1.401(a)(9)-2(b)(2)(v); age 73 is proposed, not final"},{"bornFrom":"1960-01-01","applicableAge":75}] years of age by date of birth (2026, from 2023-01-01) verified 2026-10-31 fresh https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-2; next expected change 2027-01-01