This preface introduces the book, Transforming biomedical informatics and health information access: Don Lindberg and the U.S. National Library of Medicine. The preface includes information about the book’s development process and intended audiences. The book’s contributions comprise four thematic sections. The first section documents advances in biomedical informatics during Dr. Lindberg’s career, emphasizing contributions made by teams of talented individuals at the U.S. National Library of Medicine (NLM). The second section describes how NLM’s creation of new access methods to diverse biomedical databases improved information access for health care professionals, biomedical researchers, and the public. The third section explains how NLM outreach programs improved access to health information among underserved audiences and communities. The fourth (and more informal) section provides brief memoirs about Dr. Lindberg’s life, character, and humanism.