BACKGROUND: Accountable care organizations (ACOs), patient-centered medical homes (PCMHs), and the meaningful use of electronic health records (EHRs) generated particular attention during the last decade. Translating these reforms into meaningful increases in population health depends on improving the quality and clinical integration of primary care providers (PCPs). However, if these innovations spread more quickly among PCPs in urban and wealthier areas, then they could potentially worsen existing geographic disparities in health outcomes. OBJECTIVE: To determine the market penetration of Medicare Shared Savings Program (MSSP) ACOs, PCMHs, and the meaningful use of EHRs among PCPs across urban and rural counties in Ohio. DESIGN: Retrospective, observational study of the percent of PCPs in a county who are affiliated with PCMH, ACO, and meaningful use (MU) of EHR. PARTICIPANTS: PCPs in all of Ohio's 88 counties from 2011 to 2015. MAIN MEASURES: Primary care market penetration of ACO, PCMH, and meaningful use of EHR KEY RESULTS: In 2015, the Ohio primary care market penetration of PCMH was 23.4%, ACO was 27.7%, MU stage 1 was 55.8%, and MU stage 2 was 26.6%. During the study period, PCMH and ACO market penetration increased faster in urban counties relative to rural counties, and market penetration of meaningful use of EHR increased faster in rural counties. CONCLUSIONS: Market penetration of PCMH and ACOs increased faster in urban markets compared to rural markets. However, the adoption of EHRs increased faster in rural markets. The results are a cause for optimism as well as a call to action: although recent efforts to increase PCMH and ACO adoption were less effective among the rural population in Ohio, federal programs to accelerate adoption of EHRs were overwhelmingly successful in rural areas.