Participation in the Comprehensive Primary Care Plus Initiative

This study analyzes patterns of participation in the Comprehensive Primary Care Plus initiative which is the largest voluntary primary care payment and delivery reform model tested to date. Of the nearly 20,000 primary care practices within the 18 regions selected by the Centers for Medicare and Medicaid Services for CPC+ implementation, 22 percent applied to participate. CMS accepted all applicants that met their minimum criteria, reflecting 15 percent of all primary care practices in the regions. Participation rates varied across the 18 regions from 2 percent to 34 percent. The Mathematica research team found that applicant practices, while diverse, were more likely to be larger, to be owned by a hospital or health system, to have experience with transformation efforts, and to be located in urban areas than practices that did not apply. Applicants also generally served slightly healthier and more advantaged Medicare fee-for-service beneficiaries. Overall, participating practices were not necessarily representative of all primary care practices in their region, underscoring the need to further engage practices that are small, independent, in rural areas, and lack experience with practice and payment transformation models, and the need to extrapolate evaluation results carefully.