Medicare is health insurance program for people age 65 or older. Certain people younger than age 65 can qualify for Medicare, too, including those who have disabilities and those who have permanent kidney failure or amyotrophic lateral sclerosis (Lou Gehrig’s disease).

The program helps with the cost of health care, but it does not cover all medical expenses or the cost of most long-term care.

Medicare is financed by a portion of the payroll taxes paid by workers and their employers.

It also is financed in part by monthly premiums deducted from Social Security checks.

The Centers for Medicare & Medicaid Services is the agency in charge of the Medicare program.

Medicare has four parts:

• Hospital insurance (Part A) that helps pay for inpatient care in a hospital or skilled nursing facility (following a hospital stay), some home health care and hospice care.

• Medical insurance (Part B) that helps pay for doctors’ services and many other medical services and supplies that are not covered by hospital insurance.

• Medicare Advantage (Part C) formerly known as Medicare + Choice plans are available in many areas.   People with Medicare Parts A and B can choose to receive all of their health care services through one of these provider organizations under Part C.

• Prescription drug coverage (Part D) that helps pay for medications doctors prescribe for treatment.