1970:
• Medicare Part A deductible: $52/year
• Medicare Part B premium: $4/month
• Total Medicare population: 20.4 million beneficiaries

1972: October 30, 1972 President Nixon signed the Social Security Amendments of 1972 (PL 92-603), the first major adjustment to Medicare after its enactment. Medicare eligibility was extended to individuals under age 65 with long-term disabilities (who were receiving SSDI payments for two years) and to individuals with end-stage renal disease (ESRD). The amendments also established professional standards review organizations (PSROs) to review patient care, encouraged the use of health maintenance organizations (HMOs), and gave Medicare the authority to conduct demonstration programs.

1973: Medicare coverage began for individuals receiving Social Security Disability Insurance (SSDI) cash payments for two or more years. Nearly 2 million people under age 65 with long-term disabilities or ESRD were covered.