Medicare is the federal health insurance program for seniors older than 65, who have worked full time for at least 10 years.

Medicare has four parts:

•Part A, which is free for most people, helps cover hospitalization, care in a skilled nursing facility, hospice care and some home health care.

•Part B, which costs about $100 a month, covers outpatient services such as doctor’s visits, lab tests, preventive care, some surgeries, clinical trials, mental health care and durable medical equipment and supplies.

•Part C, also known as Medicare Advantage, varies in cost and allows individuals to enroll in Medicare health plans sold by private insurance companies that contract with Medicare.

•Part D helps cover prescription drug costs.

The total amount a Medicare-covered senior may end up paying for his or her health care will depend on a variety of factors, including:

•The kind of care and how often it is needed.

•The type of Medicare coverage chosen.

•Whether a doctor agrees to charge the patient the same amount that Medicare will pay for a service.

•Whether there are other insurance policies to fill gaps in coverage.

Medicaid is a health insurance program run by individual states and partially funded by the federal government. It is the insurance of last resort for low-income individuals, including seniors.

Certain services are covered in every state, including:

•Laboratory and X-ray services

•Inpatient hospital services

•Outpatient hospital services

•Physician services

•Skilled nursing facility services

•Some home health care services

•Transportation to medical care

•Prescription drugs

Children receive additional Medicaid benefits, which also cover some adults:

•Physical therapy

•Eye doctor visits and glasses

•Audiology and hearing aids

•Podiatry services

•Prosthetic devices

•Mental health services

•Dental services

•Hospice services

•Some assisted living services

Private health insurance policies can be purchased by individuals or provided by employers. Most employer-sponsored policies end when a person retires, unless they are part of an employee’s pension or union plan, so private health insurance covers a small percentage of seniors.

Medigap is a supplemental Health Insurance for Seniors. Medigap policies help pay out-of-pocket expenses for deductibles, co-payments and coinsurance that Medicare does not. Medigap policies are sold by private insurance companies and are applied after Medicare pays its share of the approved amount for covered health care costs.