Medicare is a federal health insurance program in the United States primarily for people who are 65 or older. It also covers certain younger individuals with disabilities, as well as patients with End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS). Medicare is divided into four parts:

• Part A (Hospital Insurance): Covers inpatient hospital stays, skilled nursing facility care, hospice care, and some home health care.

• Part B (Medical Insurance): Covers certain doctors' services, outpatient care, medical supplies, and preventive services.

• Part C (Medicare Advantage Plans): These are private insurance options that cover hospital and medical costs, often including additional benefits like prescription drug coverage.

• Part D (Prescription Drug Coverage): Helps cover the cost of prescription medications.

Medicare is different from private insurance as it doesn't offer plans for couples or families.