He has nearly 30 years' experience as a doctor and former associate professor of medicine, specializing in internal and hospital medicine and related end-of-life care. He is passionate about helping patients and medical professionals understand end-of-life and how to deal with it. In his book, At Death's Door: End of Life Stories from the Bedside (Rowman & Littlefield Publishers, March 2017), Dr. Sepulveda shares his first-hand accounts of working with dying patients, exposing a profound lack of acceptance of death even under the most obvious circumstances. At Death's Door has been adapted for both a TV pilot on end-of-life care featuring a few of the most dramatic stories from the book, as well as a documentary.