Medicare is a national health insurance program in the United States, begun in 1965 under the Social Security Administration (SSA) and now administered by the Centers for Medicare and Medicaid Services (CMS). It primarily provides health insurance for Americans aged 65 and older, but also for some younger people with disability status as determined by the SSA, including people with end stage renal disease and amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease).