Medicare is a health insurance program for people 65 years of age and older, some disabled people under 65 years of age, and people with end-Stage Renal Disease (permanent kidney failure treated with dialysis or a transplant). Medicare has two parts. Part A is hospital insurance. Most people do not have to pay for Part A. Part B is medical insurance. Most people pay monthly for Part B. Everyone eligible for Social Security Disability Insurance (SSDI) benefits is also eligible for Medicare after a 24-month qualifying period. The first 24 months of disability benefit entitlement is the waiting period for Medicare coverage. During this qualifying period for Medicare, the beneficiary may be eligible for health insurance through a former employer.