Objective. State Medicaid programs are obligated by federal law to ensure that enrolled children have access to care and services to the same extent as other children in the same geographic area. Because most children in the United States receive health care from private primary care physicians, participation by private, office-based primary care pediatricians is critical to meeting this equal access obligation. The objective of this study was to document variations in Medicaid participation of private office-based primary care pediatricians across states and to examine the effects of payment levels, prevalence of capitated Medicaid payment, and paperwork concerns on participation. Methods. Survey data collected from 3773 primary care pediatricians who practice in private office-based settings were analyzed with Medicaid physician payment data from other sources. Univariate analyses and a multiple regression were used to examine the effects of payment level, prevalence of capitated Medicaid payment, and paperwork concerns on private primary care pediatricians' participation in state Medicaid programs. Results. Results revealed substantial state-to-state variation in respondents' participation in Medicaid. Univariate analyses found that participation increased with state Medicaid payment levels but decreased as the proportion of Medicaid enrollees with primary care capitated payments rose and as paperwork concerns increased. With physician workforce held constant, a regression analysis showed that pediatrician participation in Medicaid increased significantly with Medicaid payment but decreased as the proportion of capitated Medicaid patients increased and as paperwork concerns rose. Conclusions. This study found that low payment, capitation, and paperwork concerns all relate to low Medicaid participation by primary care office-based pediatricians. It behooves state policy makers to address these 3 factors to ensure sufficient primary care physician capacity to serve appropriately children who are enrolled in state Medicaid programs.
