The National Health Service Corps (NHSC) was created in 1970 to provide primary health care clinicians for the underserved. The article includes a review of the peer-reviewed and intragovernmental literature on the NHSC program from 1971 to 1998 and also presents a current profile of the program. Despite significant increases in NHSC field strength since 1991, the 2,439 clinicians meet only 12% of the need for primary health care providers in underserved areas. While the NHSC has successfully addressed clinician diversity and retention issues, community and site development remain barriers to increasing access. Most communities in need are not ready to recruit and support clinicians. The NHSC of the next millennium must work with the neediest communities to reach the appropriate stage of readiness. Only after completing the necessary "preplacement" activities can the NHSC assist in the recruitment and placement of clinicians to increase access.