The simple answer is that both an MD (Doctor of Medicine) and a DO (Doctor of Osteopathic Medicine) are doctors licensed to practice in the United States. They are similarly educated and certified, but there are differences in their training and philosophy of patient care.
As part of their medical education, DOs receive additional musculoskeletal training known as osteopathic manipulative treatment. MDs receive more of the traditional training. Both can practice in any medical specialty.
The two degrees have much in common, both in terms of training and practice.
Pre-med students follow the same undergraduate path — obtaining a bachelor’s degree, completing pre-med coursework and taking the MCAT. Then they attend four years of medical school, followed by a residency program that ranges from three to seven years, depending on the specialty.
Both MD and DO physicians are licensed by the same state licensing boards and held to the same requirements for practicing medicine. Both can prescribe medications and treat patients in all 50 states. Moreover, while DO doctors tend to become general practitioners, they may pursue careers in any chosen specialty, including surgery.