When Was Medicare Part B Enacted? 
Medicare was enacted in 1965 by the Lyndon B. Johnson administration . The program went into effect in 1966 and was originally administered by the Social Security Administration . Today Medicare is administered by CMS `` Centers for Medicare and Medicaid Services '' . Medicare covers eligible persons who are over 65 years of age or under 65 for disabled individuals . For more on the history of medicare please visit www.medicare.gov 