An independent agency within the Executive Branch of the United States Government. It administers a national social insurance program whereby employees, employers, and the self-employed pay contributions into pooled trust funds. Part of the contributions go into a separate hospital insurance trust fund for workers at age 65 to provide help with medical expenses. Other programs include the supplemental social security income program for the aged, blind, and disabled and the Old Age Survivors and Disability Insurance Program. It became an independent agency March 31, 1995. It had previously been part of the Department of Health, Education, and Welfare, later the Department of Health and Human Services. (From United States Government Manual, 1994-95)

Government sponsored social insurance programs.

Insurance designed to compensate persons who lose wages because of illness or injury; insurance providing periodic payments that partially replace lost wages, salary, or other income when the insured is unable to work because of illness, injury, or disease. Individual and group disability insurance are two types of such coverage. (From Facts on File Dictionary of Health Care Management, 1988, p207)

The term "United States" in a medical context often refers to the country where a patient or study participant resides, and is not a medical term per se, but relevant for epidemiological studies, healthcare policies, and understanding differences in disease prevalence, treatment patterns, and health outcomes across various geographic locations.