Congress, policy analysts, and groups representing physicians have raised questions about beneficiary access to Medicare physician services. At the same time, high levels of spending for health care in some parts of the country, and rapid increases in spending for physician services, have been identified as factors that threaten the long-term fiscal sustainability of the Medicare program. This report: (1) examines whether, from 2000 through 2008, beneficiaries had problems accessing physician services; (2) identifies areas of the country in which Medicare beneficiaries are potentially over-served by physicians; and (3) describes characteristics that distinguish the potentially over-served areas from other areas in the nation. Charts and tables.