Endocrine Self-Assessment Program (ESAP), Reference Edition 2021 is a self-study resource for physicians and health professionals wanting a self-assessment and broad review of endocrinology. It consists of approximately 120 multiple-choice questions in the areas of endocrinology, diabetes, and metabolism. Correct answers for each question are extensively discussed, with references provided, and the volume also contains a comprehensive syllabus. CME, MOC, online module not included. Updated annually.