1935: All workers in commerce and industry under age 65 (covered after 1936).
1939: Age restriction eliminated (effective 1940).
1950: Regularly employed farm and domestic workers, nonfarmself-employed (except members of professional groups), U.S. citizens employed abroad by U.S. employers, and workers in Puerto Rico and the U.S. Virgin Islands (effective 1951).
1954: Self-employed farm workers, self-employed professionals (with some exceptions), and home workers (effective 1955).
1960: U.S. citizens employed in the U.S. by foreign governments or international organizations, and workers in Guam and American Samoa (effective 1961).
1965: Interns, self-employed physicians, and employees with tip income (for employee share of tax only) (effective 1966).
1982: Federal employees, for Medicare Part A (Hospital Insurance) only (effective 1983).
1983: Federal employees hired after 12/31/1983, including executive, legislative, and judicial branch employees, members of Congress, president, vice president, sitting federal judges, most executive-level political appointees, newly hired employees of nonprofit organizations, and U.S. residents employed abroad by U.S. employers (effective 1984).
1990: State and local government employees not under a state or local government retirement system (with some exceptions) (effective July 1991).
1994: Police and firefighters under a public retirement system can be covered for Social Security in all states (effective August 1994).
