Richard M. Caplan was born in Des Moines, Iowa, on July 16, 1929. Caplan received a B.S. degree in psychology from Iowa State University in 1949. Having played piano since the age of seven, he pursued the M.A. degree in music composition from the University of Iowa in 1951. He took the M.D. degree from the University of Iowa in 1955. Dr. Caplan served as a flight surgeon in the U. S. Air Force from 1955 to 1958. He made his residency in the Department of Dermatology at the University of Michigan Medical Center. Caplan joined the faculty of the State University of Iowa College of Medicine as assistant professor of dermatology in 1961. He was named full professor in 1969. Caplan was director of the Office of Medical Education in the Department of Dermatology at Children's Hospital. He also served as associate dean for continuing education in the College of Medicine.

Caplan served on many University committees. This included the Committee on Campus Instructional TV, Committee on International Education, and the Foreign Language Council. Caplan was appointed by President James O. Freedman to serve on the Committee for Appropriate Uses of the University (CAUU), which examined CIA recruitment on campus during the mid-1980s. He served on the advisory board for the University of Iowa Press (1986-1990). He also served on the advisory committee for Channel 28 Programming, which guided the operations of the University cable TV channel (1982-1985), as well as the Campus Instructional TV Committee (1987-1988).

Dr. Caplan taught courses in the medical humanities program and introduced courses in biomedical ethics. He has guided the History of Medicine Society of distinguished speakers since 1974. His numerous awards include the Hancher-Finkbine Medallion.

In addition to his University activities, Caplan served on the planning committee of the Iowa Medical Society, and wrote a column in the society's journal, Iowa Medicine. He served on committees of the American Medical Association, the American Academy of Dermatology, and the Society for Health and Human Values. Caplan retired in 1996, after 35 years at the University of Iowa. In honor of his service, the Richard M. Caplan Chair in Biomedical Ethics and Medical Humanities was established in 1998.

Caplan is an authority on Sir Arthur Conan Doyle's fictional character, Sherlock Holmes and he published a manuscript on the subject. He became a member of the New York City-based Baker Street Irregulars in 1984, a name the fans borrowed from Doyle's books. In 1988, Caplan established the Younger Stamfords, a society of Sherlock Holmes fans in Iowa City.

Caplan married Ellen Sideman, a librarian, in 1952 and the couple had four sons, David, Joel, Daniel, and Aaron.