Medicare is a federal program that provides health insurance to 44 million people -- about one in seven Americans.

People aged 65 and older are automatically entitled to Medicare if they or their spouse are eligible for Social Security. This group accounts for about 37 million Medicare beneficiaries.

People younger than 65 can qualify for Medicare if the Social Security Administration determines they are disabled. This group comprises about 7 million Medicare beneficiaries.

Among those eligible for Medicare disability coverage are people with HIV or AIDS. They represent about 100,000 Medicare beneficiaries nationwide, including about 8,000 in South Florida.

MEDICARE IS COMPRISED OF FOUR PARTS

Part A, hospital services

Part B, outpatient care

Part C, managed care

Part D, prescription drugs

FRAUD PLAGUES PART B

In urban areas such as South Florida, fraud has plagued Part B, which makes up about 40 percent of Medicare's $432 billion annual budget. It covers claims submitted for outpatient care by physicians, health clinics, medical equipment suppliers and others.