You may see different letters after your doctor’s name indicating what kind of a physician he or she is. The Dr. title is the same, but the terms Doctor of Medicine (M.D.) and Doctor of Osteopathic Medicine (D.O.) refer to the type of medical school the physician attended, says UCLA Health.

Both M.D.s and D.O.s are fully qualified physicians licensed to diagnose, treat, and prescribe medicine in all 50 states. The primary distinction lies in their training philosophies. M.D.s follow the allopathic, or traditional model of medicine, which emphasizes diagnosing and treating diseases primarily with medications and surgery, while D.O.s receive additional instruction in osteopathic manipulative medicine and take a more holistic approach, often considering lifestyle and preventive care as integral components of patient health.

It’s a myth to believe that an M.D. is superior to a D.O., according to studies. For example, researchers at UCLA Health found that patients had similar outcomes with both types of doctors. Here’s a summary of the findings of hospital data involving 329,500 people who were 65 or older between 2016 and 2019:

• Doctor to patient breakdown. Researchers said 77% of patients were treated by M.D.s and 23% were treated by D.O.s. The D.O.s in the study were on average a few years younger than M.D.s and slightly more likely to be women.

• Mortality rates. Patient mortality rates were 9.4% among patients treated by M.D.s compared with 9.5% for those treated by D.O.s. Hospital readmission rates were 15.7% with M.D.s versus 15.6% with D.O.s.

•Cost. Spending by Medicare to cover the doctors’ bills differed by only a dollar, at $1,004 vs. $1,003.

• Length of hospital stay. The average length of stay was 4½ days for both groups of patients.

The findings were published in the Annals of Internal Medicine.

“Our hypothesis was that patient outcomes would be similar between M.D.s and D.O.s, given that medical education programs are quite standardized between allopathic and osteopathic medical schools,” said Dr. Yusuke Tsugawa, associate professor of medicine at the David Geffert School of Medicine at UCLA who was the senior author of the study.  

According to the New York Times, the number of osteopathic doctors has risen dramatically by 70% in the past decade and is expected to continue expanding. More than 25% of all medical students in America are training to become D.O.’s because of limited access to traditional medical schools and the opening of more osteopathic schools.

Osteopathic physicians have risen to extraordinary positions during this time, leading top medical health systems, overseeing NASA’s medical team and even overseeing the medical care of the U.S. president during the last three administrations. While D.O.s attend separate medical schools, the curriculum is much the same and many take the same board exams as well as attend the same residency programs as M.D.s

You tend to find more D.O.s in rural areas, and as primary care providers, says the Times. Nearly 60% of D.O.s are primary care providers. Helping those underserved by the medical establishment is a prime osteopathic philosophy, say experts.

“It may be that the students who entered osteopathic schools have an original preference for primary care and rural practice,” said Tsugawa, who is also an associate professor of health policy and management at the UCLA Fielding School of Public Health.