About one in six people expected to enroll in Medicaid under health reform expansions and nearly one in ten expected to enroll in qualified health plans through the health insurance Marketplaces will have spent some time in jail during the past year. People who have spent time in jail frequently cycle in and out of incarceration; have high rates of chronic physical, mental health, and substance use conditions; and historically have been uninsured and without access to continuous health care. The Affordable Care Act may not change the quality of health care in jails, but its provision of better access to care before and after people are incarcerated could have positive long-term effects on both the health of those individuals and overall health care costs. Achieving these results will require careful planning and coordination among jail health care programs, Medicaid, and Marketplace health plans. The use of electronic health records by jails and community providers could help ensure that treatments are consistent no matter where a patient resides. Policy makers and health plans could also ensure continuity of care by including in their networks some of the same safety-net providers that are under contract to furnish care to jail inmates.