Medicare Assignment: Concept referring to the standardized fees for services rendered by health care providers, e.g., laboratories and physicians, and reimbursement for those services under Medicare Part B. It includes acceptance by the physician.Medicare: Federal program, created by Public Law 89-97, Title XVIII-Health Insurance for the Aged, a 1965 amendment to the Social Security Act, that provides health insurance benefits to persons over the age of 65 and others eligible for Social Security benefits. It consists of two separate but coordinated programs: hospital insurance (MEDICARE PART A) and supplementary medical insurance (MEDICARE PART B). (Hospital Administration Terminology, AHA, 2d ed and A Discursive Dictionary of Health Care, US House of Representatives, 1976)Centers for Medicare and Medicaid Services (U.S.): A component of the Department of Health and Human Services to oversee and direct the Medicare and Medicaid programs and related Federal medical care quality control staffs. Name was changed effective June 14, 2001.Medicare Part B: The voluntary portion of Medicare, known as the Supplementary Medical Insurance (SMI) Program, that includes physician's services, home health care, medical services, outpatient hospital services, and laboratory, pathology, and radiology services. All persons entitled to Medicare Part A may enroll in Medicare Part B on a monthly premium basis.Medicare Part A: The compulsory portion of Medicare that is known as the Hospital Insurance Program. All persons 65 years and older who are entitled to benefits under the Old Age, Survivors, Disability and Health Insurance Program or railroad retirement, persons under the age of 65 who have been eligible for disability for more than two years, and insured workers (and their dependents) requiring renal dialysis or kidney transplantation are automatically enrolled in Medicare Part A.United StatesFee-for-Service Plans: Method of charging whereby a physician or other practitioner bills for each encounter or service rendered. In addition to physicians, other health care professionals are reimbursed via this mechanism. Fee-for-service plans contrast with salary, per capita, and prepayment systems, where the payment does not change with the number of services actually used or if none are used. (From Discursive Dictionary of Health Care, 1976)