The purposes of this study were 1) to review the Medical Nutrition Therapy (MNT) Act of the United States, 2) to introduce the efforts of the American Dietetic Association (ADA) to expand the Medicare coverage for MNT and 3) to provide information about the reimbursement under Medicare Part B for the cost of MNT. The MNT Act defined MNT services as "the nutritional diagnostic, therapeutic, and counseling services provided by a Registered Dietitian or nutritional professional for the purpose of managing diabetes or renal diseases". Also, the MNT Act defined "conditions for coverage of MNT", "limitations on coverage of MNT", and "qualifications of MNT service provider". To expand the coverage of Medicare to include MNT, the ADA realized the need for development of a protocol for MNT, as well as studies to evaluate the effectiveness and cost-effectiveness of the MNT protocol developed. Therfore, the ADA supported the studies to develop a strong database of scientific investigations of nutritional services. Furthermore, the ADA needed credible data that could be used by policy makers, so the ADA contracted with the Lewin Group to carry out the study to gather the additional data needed to strengthen the ADA's position. In the report of the Lewin Group, which was entitled, "The Cost of Covering Medical Nutrition Therapy under Medicare: 1998 through 2004", it was concluded, that if coverage for MNT in the Part B portion of Medicare had begun in 1998, by 2004, approximately $ 2.3 billion would have been saved through reduced hospital spending under Part A of Medicare ($ 1.2 billion) and reduced physician visits under Part B ($ 1.1 billion). Effective January 1 2002, the US Congress extended Medicare coverage to include MNT to beneficiaries with diabetes or renal diseases. The Centers for Medicare and Medicaid Services (CMS) established the duration and frequency for the MNT based on published reports or generally accepted protocols (for example, protocols suggested by the ADA). The number of hours covered by Medicare is 3 hours for the initial MNT and 2 hours for a follow-up MNT. In 2002, a Medicare coverage policy was made to define the Physician's Current Procedural Terminology (CPT) codes 97802, 97803, and 97804 for MNT.