The prescribing on inappropriate medications to older adults is extremely common in the United States. Older adults are twice as likely as younger patients to be hospitalized as a result of drug-related problems. Fortunately, more than 50% of these admissions are preventable. NUDGE-EHR is a pragmatic randomized controlled trial using an adaptive study design to allow for rapid within trial learning and design modification of EHR decision support to reduce inappropriate prescribing for older adults.