background. Enrollment in the State Children's Health Insurance Program (SCHIP), created under the federal Balanced Budget Act of 1997, had a distressingly slow start and varied substantially county-to-county in many states, including Pennsylvania.

methods. We performed a quantitative county-level analysis of barriers to enrollment in Pennsylvania's Children's Health Insurance Program (CHIP) for the year 2000, seven years after it was implemented and three years after federal SCHIP legislation. Using multivariate regression analysis with a county as the unit of observation, we modeled enrollment in SCHIP as a function of accessibility to health care, availability of clinicians, and community economic health.

results. High clinic density and Medicaid managed-care membership predicted SCHIP enrollment success, while female head-of-household predicted SCHIP enrollment failure. A principal-components factor analysis revealed four underlying barriers to enrollment: accessibility, availability, affordability, and effort.

conclusions. The most formidable barriers to SCHIP enrollment success in Pennsylvania were not programmatic; they were correlates of poverty itself.