A doctor of osteopathic medicine (D.O.) is a fully trained and licensed doctor who has attended and graduated from a U.S. osteopathic medical school. A doctor of medicine (M.D.) has attended and graduated from a conventional (allopathic) medical school. The major difference between osteopathic and allopathic doctors is that some osteopathic doctors provide manual medicine therapies, such as spinal manipulation or massage therapy, as part of their treatment. After medical school, both M.D.s and D.O.s must complete residency training in their chosen specialties.