CATALYST is a longitudinal formative assessment platform based on cognitive learning principles designed to promote more durable and complex learning. CATALYST offers practice-relevant content at spaced intervals with immediate feedback and related reference materials. It also offers mobile accessibility, improvement resources and short questions to fit busy schedules. CATALYST can be customized to meet client requirements and presents an alternative format for low/medium-stakes assessments as well as more high-stakes examinations traditionally administered by specialty medical boards.