Seeing the letters M.D. after someone’s name signals that they’ve gone through the grueling education and training required to become a licensed medical doctor. But seeing the letters D.O. may spark questions, like…what is a D.O., actually? Are they similar to M.D.s? And, maybe most importantly, when might you benefit from seeing a D.O.?
Both M.D.s and D.O.s are fully licensed physicians who go through four years of medical school, a licensing exam, and a residency program. Overall, the differences between the two lie in their training and philosophy, but even then, there is plenty of overlap.
An M.D. (doctor of medicine) practices traditional Western medicine, sometimes referred to as conventional medicine, which is focused on the treatment and diagnosis of human diseases. A D.O. (doctor of osteopathic medicine) practices osteopathic medicine, which is focused on disease prevention and the musculoskeletal system. But, in reality, most M.D.s also focus on disease prevention, just as most D.O.s also focus on treatment and diagnosis. In fact, a 2007 study published in the peer-reviewed journal Osteopathic Medicine and Primary Care looked at a nationally representative sample of general and family medicine patient-provider interactions between 2003-2004. They found no significant difference between D.O. and M.D. physicians when it came to their time spent with patients, counseling of patients, or preventive care.
D.O.s, like M.D.s, can see patients, prescribe medications, and perform surgeries, according to the U.S. National Library of Medicine. You know, the usual doctorly duties. There are a lot of similarities between the two, but there are also some differences. Here, we’ll go over a few distinctions between a D.O. and an M.D.
In order to become licensed, both D.O.s and M.D.s must complete four years of medical school, according to the U.S. National Library of Medicine. They typically spend the first two years studying and then two years doing clinical rotations, the American Osteopathic Association (AOA) explains.
One major difference between an M.D. and a D.O. is where they go to medical school. While M.D.s go to one of 152 accredited medical schools, D.O.s attend one of 35 osteopathic medical schools in the United States. These institutions are accredited by the AOA’s Commission on Osteopathic College Accreditation (COCA), which is recognized by the U.S. Department of Education. M.D. programs are accredited by a different body: the Liaison Committee on Medical Education.
In general, M.D. schools are often considered to be more prestigious. According to the 2019 U.S. News & World Report ranking of accredited medical schools—both conventional (M.D.) and osteopathic (D.O.)—the top 50 schools in research and primary care were all M.D. programs. Their ranking included 124 medical schools that were accredited as of 2017 and also submitted information for ranking. The rankings are based on a weighted average of various indicators, including things like: quality assessment (as rated by both peers and residency program directors within each school), student selectivity (as evidenced by median test scores and acceptance rate), and the student-to-faculty ratio. Research programs were also ranked based on the amount of research grants awarded to the school, while primary care programs were also ranked based on the percentage of graduates entering primary care residencies.
Adding to that, most of the country’s highest-ranked teaching and research hospitals are affiliated with M.D. schools—including the 20 best in the nation as rated by U.S. News & World Report. Though it’s worth noting here when considering these rankings that there are many more M.D. schools that D.O. schools in the country.
There also appears to be a slight overall difference in the average academic scores of the medical students accepted to either D.O. or M.D. colleges, based on data from the American Association of Colleges of Osteopathic Medicine (AACOM) and the Association of American Medical Colleges (AAMC). In 2017, the average all-coursework GPA for people accepted to and enrolling in D.O. programs was 3.56, compared to 3.71 for those accepted to M.D. programs. And the average MCAT (Medical College Admission Test) score for accepted D.O.s was 503.05, compared to 510.40 for M.D.s.
Of course, none of this is likely to be information that you’d require your doctor to disclose to you—regardless of their degree—but it helps to illustrate just how competitive it can be to be accepted into an M.D. program these days, which is one reason why some people might be more attracted to a D.O. program.
Licensing, Residencies, and Board Certifications
Both M.D.s and D.O.s have to pass a licensing exam before graduating. For D.O.s, this is the Comprehensive Osteopathic Medical Licensing Examination of the United States (COMLEX-USA), according to the AACOM. This test, administered by the National Board of Osteopathic Medical Examiners (NBOME), is accepted by the state licensing board in all 50 states, the District of Columbia, and all U.S. territories, according to the AACOM.
After passing their licensing exams, D.O.s choose a specialty to pursue—anything from neurosurgery or emergency medicine to anesthesiology or psychiatry—then begin their graduate medical education (GME).
This involves entering residency training, as M.D.s do, for at least three years, according to the AACOM. Some will opt to go on to a fellowship program once they finish residency.
Some D.O.s end up matching into osteopathic residencies (accredited by the AOA) while others match into M.D. residencies (accredited by the ACGME). Although it may be slightly harder to get accepted into an ACGME-accredited residency when coming from a D.O. program versus an M.D. program: While 94.3 percent of M.D. grads successfully matched into an ACGME residency in 2018, 81.7 percent of D.O.s did the same, according to the NRMP.
Interestingly, by June 30, 2020, the two systems will merge under the ACGME, according to the AOAmeaning all M.D.s and D.O.s will match through the NRMP and train alongside each other in residencies.
Finally, D.O.s may opt to become board-certified in their areas of practice in order to demonstrate their specialized expertise, like their M.D. counterparts. Certifying boards for D.O.s and M.D.s are different, though. (Despite the residency merger, there are no public plans to fold these boards together.) While M.D.s are certified by one of the 24 member boards of The American Board of Medical Specialties, D.O.s are certified by one of the AOA’s 18 specialty certifying boards. Criteria vary across the specialties and subspecialties but usually involve passing an exam.
Training and Philosophy
The main difference in the medical education between the two groups is that D.O. programs are generally more focused on preventive care. Although D.O.s practice in every field of medicine, a slight majority (nearly 57 percent) go into primary care specialties, while less than one-third of M.D.s. do the same. D.O. training also includes special attention to the musculoskeletal system, according to the National Center for Complementary and Integrative Health (NCCIH), which we’ll get into more in a bit.
According to the AOA, there are four tenets of osteopathic medicine:
The body is a unit; the person is a unit of body, mind, and spirit.
The body is capable of self-regulation, self-healing, and health maintenance.
Structure and function are reciprocally interrelated.
Rational treatment is based upon an understanding of the basic principles of body unity, self-regulation, and the interrelationship of structure and function.
In practice, this means that D.O.s generally focus on evaluating different body parts and systems in the context of each other, viewing them all as interconnected, and also considering emotional and mental health as well, Octavia Cannon, D.O., a board-certified ob/gyn in North Carolina and president of the American College of Osteopathic Obstetricians and Gynecologists, tells SELF. “D.O.s are trained to look at the entire patient to determine diagnosis and treatment, not just the specific complaint,” she explains.
That’s not to say M.D.s don’t also focus on the whole patient, though. “M.D.-granting medical schools understand that patient care is often a complex and personal issue. For treatment to be most effective, a holistic approach to a patient’s condition should be followed,” Janis Orlowski, M.D., chief health care officer at the AAMC, tells SELF.
While M.D.-granting medical schools focus on traditional evidence-based medicine, their curricula also include holistic approaches. “Students receive interprofessional training that brings together several different approaches to patient care delivery that can be more comprehensive and can improve the overall health outcomes of a patient,” says Dr. Orlowksi. As we mentioned, there’s a lot of overlap.
Focus on the Musculoskeletal System
Another important distinction: The D.O. philosophy places a significant emphasis on the musculoskeletal system (your nerves, muscles, and bones) as a cornerstone of health.
Because of this, D.O.s spend at least 200 hours during their medical education getting additional training in a technique called osteopathic manipulative medicine (OMM).
Osteopathic manipulative medicine involves hands-on movement of the musculoskeletal system. Also called osteopathic manipulative treatment (OMT), OMM is a kind of manual therapy some D.O.s use to address mechanical issues in the body, according to the NCCIH. It involves manipulating a person’s muscles and joints with a variety of techniques like stretching and gentle pressure, according to the AOA.
For instance, a primary care D.O. may use OMM to diagnose and address the root cause of common complaints like lower back pain and headaches, issues that often originate from other parts of the body, Mikhail Varshavski, D.O., a board-certified family medicine physician at the Atlantic Health System’s Overlook Medical Center, tells SELF. “It is not uncommon to find a patient suffering from back pain originating from tight muscles in the hips,” he explains, “or headaches resulting from poor posture leading to muscular dysfunction in the [paraspinal muscles in the back].” In 2017, the Journal of Family Practice reviewed various meta-analyses and found that patients who received OMM for lower back pain reported decreased pain and improved function (compared to patients who received no treatment, other treatments, or “sham” OMM).
However, not all D.O.s employ OMM on a regular basis. Overall, it appears as though the number of D.O.s practicing this method is declining. Although there is not much data on the subject, a 1998 mail-in survey of 955 D.O.s published in the The Journal of the Association of American Medical Colleges found that over 50 percent of the respondents said that they use OMM on less than 5 percent of their patients. A similar survey published in the Journal of the American Osteopathic Association in 1997 found that only 6 percent of the 1,055 respondents reported using OMM on over half their patients.
It’s possible that some of the confusion around D.O.s stems from this focus on OMM and the underlying emphasis on osteopathy. In the United States, OMM is just one tool in a D.O.’s treatment kit. But in other countries, a D.O. is typically someone trained and licensed only in the area of OMM, per the AACOM. They are not full-practice physicians.
This has led some people to believe that this is the case for D.O.s in the United States, Dr. Varshavski tells SELF. “On my social media channels, I have had some misinformation pop up from time to time from those who do not take the time to research and understand the D.O. degree thoroughly,” he explains.
D.O. Degrees Are Increasing
There aren’t currently a lot of D.O.s out there—M.D.s represent around 91.3 percent of all licensed physicians in the United States, according to a Federation of State Medical Boards (FSMB) census done in 2016.
But D.O. ranks are growing quickly. Over the last 10 years, there has been a 158.9 percent increase in D.O. graduates (compared to a 17 percent increase in M.D. graduates), according to the ACGME. And one in four students currently in medical school is studying to become a D.O., according to a 2017 AOA report.
Why the massive increase? There may simply be a growing interest in the approach to wellness emphasized in osteopathic medicine, as well as something of a snowball effect: The more D.O.s there are, the more reputable and recognizable the degree becomes, the more people want to become D.O.s, and so on.
But there is also the plain fact that getting into med school has become increasingly competitive, as noted earlier.
“There [is] a growing number of applicants, and the statistical expectations for M.D. programs are getting higher and higher,” medical school admissions expert Shirag Shemmassian, Ph.D., founder of Shemmassian Academic Consulting, tells SELF. Speaking anecdotally from a 15-year career working with med school hopefuls, Shemmassian says he’s found that, in general, students who recognize they don't have the exceptional test scores needed to get into an M.D. program are increasingly open to the D.O. track.
Ultimately, as Shemmassian puts it, “The interest in medicine isn’t going away—nor is the need to satisfy America's growing need for medical care.”
Choosing Your Doctor
You may have zero interest in whether your doctor has an M.D. or a D.O.—or you may have strong feelings about it. As noted, the two are very similar in many respects, but the differences may also be appealing to you for one reason or another. At the end of the day, it’s more about the individual doctor than the letters after their name.
“A degree alone does not give enough information on a doctor's abilities,” Dr. Varshavski says. “Ultimately, I think in picking a doctor you should focus most on their knowledge, bedside manner, communication, and medical experience.” In most cases, their degree will really only tell you part of that.