There are many types of payment plans, insurance plans and medical groups.

Medicare  This is a government-sponsored health insurance program for people age 65 and older. It also covers people who are permanently disabled and who have received Social Security benefits for at least two years.
    Medicare is divided into two parts:
• Part A. Hospital Insurance. This covers your inpatient hospital stay, limited skilled nursing care, part-time
  home health care and hospice for those who are eligible. It is available without payment of a premium,
  although some services require a deductible or co-insurance. Medicare Part A is administered by the Health
  Care Financing Administration (HCFA) through insurers called intermediaries.
• Part B. Medical Insurance. This covers physician services and hospital outpatient care, such as blood
  transfusions, x-rays and lab tests. There is limited coverage for medical equipment such as wheelchairs and
  walkers. Enrollment is optional and the payment of a premium is required. Medicare Part B covers 80 percent
  of allowed charges. You are responsible for the other 20 percent of allowed charges, called co-insurance. You
  must also meet a yearly deductible (currently $100) before Medicare Part B coverage applies.
      Medicare Part B is directed by the federal government through the HCFA and is funded through a monthly
  premium, which comes out of your Social Security check. It is administered through contracts with a number
  of insurers (called carriers) throughout the United States. If you need additional information, as well as a free
  handbook describing the Medicare program, contact your local Social Security office.