The widespread implementation of electronic medical records (EMRs), stimulated by the Patient Protection and Affordable Care Act, provides a major opportunity to conduct inexpensive pragmatic randomized trials1,2 that are embedded into the clinical practice of health care delivery. Electronic medical records allow health systems to identify particular types of patients, deliver targeted interventions designed to improve health, and measure how those interventions impact health care delivery and health outcomes. With optimal use of EMRs, the administrative costs of a trial need not increase with the sample size; this decoupling of costs and size facilitates large, simple, and inexpensive trials that have the potential to transform health systems into entities that learn and continuously improve.3