Although primarily associated with persons 65 years or older (who are otherwise eligible for Social Security benefits), Medicare also covers those under 65 who are “disabled” under Social Security Disability Insurance criteria or suffer from permanent kidney failure. There are other ways to qualify (e.g., over 65 and a Railroad Retirement beneficiary; under 65 and previously eligible but returned to work in the interim, etc.). It is recommended that one consult a Social Security office for current eligibility criteria.