Jails admit nearly 11 million individuals each year, including a high number of inmates with mental illnesses, infectious diseases, and chronic diseases. Since the Supreme Court’s landmark decision in Estelle v. Gamble (1976), federal and state correctional systems (including prisons, jails, and juvenile detention facilities) have been constitutionally mandated to provide “reasonably adequate” health care to the incarcerated population. Yet, unlike health care systems that provide services to the nonincarcerated population, there is no legally-mandated accreditation system for health care provided in U.S. correctional systems, including jails. As a result, jails may struggle to provide needed health care services. This may result in increased morbidity and mortality in this vulnerable population. Jail reforms are also often piecemeal and in response to inmate litigation. In this study, we propose to randomize the offer of health care accreditation via the National Commission on Correctional Health Care (NCCHC) to 40 medium-sized jails. NCCHC, the organization that pioneered standards for jail health care services, operates a voluntary accreditation program based on a set of consensus-driven standards that provide a framework for the care inmates receive. We hypothesize that the process of preparation, verification, and maintenance of accreditation will improve health care processes, inmate health outcomes, and satisfaction and retention among correctional staff, and potentially reduce recidivism, litigation, and health care costs for jails.