Criteria used to identify U.S. health manpower shortage areas (HMSAs) are reviewed. A detailed exposition is provided of the Interim-Final Regulations for designating HMSA. Literature directly related to the concepts used in the current HMSA designation criteria is also reviewed. These criteria are access, availability, need, and rational service areas. Written comments that were submitted to the Bureau of Health Manpower in response to the publication of the criteria are also addressed, and the feasibility of introducing the recommended changes is assessed. An independent analysis of the appropriateness of the criteria for identifying geographic HMSAs in an urban setting is included; the analysis is based on a database derived from the Canadian experience with universal health insurance. Attention is focused on mean utilization rates by small area, comparative utilization rates for beneficiaries living in designated HMSAs and beneficiaries living in non-HMSAs, and five measures of medical services utilization. The HMSA criteria are also assessed in light of the policy objectives that the criteria were developed to serve. Suggestions for revising the criteria for publication as final regulations are included. The text of legislation and regulations pertaining to the criteria is provided, along with comments on the regulations, and a bibliography. (SW)