What Is a DO Doctor and How Do They Differ from MDs?

A DO, or Doctor of Osteopathic Medicine, is a fully licensed physician who can diagnose illness, prescribe medication, perform surgery, and practice in every medical specialty, just like a Doctor of Medicine (MD). The core difference is that DOs receive additional training in a hands-on diagnostic and treatment approach called osteopathic manipulative treatment (OMT), and their education emphasizes a philosophy of treating the whole patient rather than isolated symptoms. In everyday clinical practice, though, the two types of doctors are far more alike than most people realize, and the gap has been narrowing for decades.

Where Osteopathic Medicine Came From

Osteopathic medicine traces back to Andrew Taylor Still, who started his career as a conventional MD on the American frontier in the 1850s. Dissatisfied with the medical practices of his era, Still developed a new approach that emphasized the musculoskeletal system’s role in health and disease. In 1892 he founded the American School of Osteopathy in Kirksville, Missouri, becoming the first Doctor of Osteopathy and launching a parallel branch of American medicine that has grown ever since.¹

Still’s original concept centered on the idea that disruptions to the flow of body fluids, particularly around the spine, could cause disease. Over the twentieth century, that notion was refined into the modern concept of “somatic dysfunction,” which both American-trained DOs and osteopaths trained abroad still consider a foundational part of their practice and teaching.² That theoretical backbone has evolved substantially since the 1890s, but it remains what distinguishes a DO education from an MD education at a structural level.

How DO and MD Training Compare

Both DOs and MDs complete four years of medical school followed by residency training. Both take national licensing exams, learn the same core sciences (anatomy, physiology, pharmacology, pathology), rotate through clinical clerkships in the same specialties, and emerge legally authorized to practice the full scope of medicine. The difference is not in what DOs learn less of. It is in what they learn more of.

DO students take all the same coursework as their MD counterparts, plus hundreds of additional hours in osteopathic principles and practice. This includes learning to use their hands to diagnose restrictions in the musculoskeletal system and to perform OMT techniques. The philosophical framing also differs: osteopathic programs tend to stress four tenets that the body functions as a unit, that it has self-healing capacity, that structure and function are interrelated, and that rational treatment follows from understanding all three.

Despite the curricular overlap, DO and MD students take different primary board exams. DOs sit for COMLEX (Comprehensive Osteopathic Medical Licensing Examination), while MDs take the USMLE (United States Medical Licensing Examination). Many DO students choose to take both. A cross-sectional study that matched scores from hundreds of students who sat for both exams found a strong correlation between the two: scores on Step 1 correlated at 0.85, and Step 2 scores correlated at 0.79.³ In practical terms, students who do well on one exam tend to do well on the other, reinforcing the idea that the two medical education tracks are testing substantially the same clinical knowledge.

What Osteopathic Manipulative Treatment Actually Is

OMT is the skill set that most visibly separates DOs from MDs. It encompasses a range of hands-on techniques in which the physician uses their hands to diagnose, treat, and sometimes prevent illness or injury. Techniques include gentle stretching, pressure, and resistance applied to muscles, joints, and fascial tissues. Some methods involve high-velocity, low-amplitude thrusts (similar to what you might associate with chiropractic adjustments), while others are extremely subtle, using the body’s own rhythmic motions.

The theoretical model underlying OMT includes the concept of spinal facilitation: the idea that a reflex loop can develop between a spinal segment and either a visceral organ or a somatic structure, creating a self-reinforcing cycle of dysfunction. Under this model, a problem in an internal organ could produce musculoskeletal symptoms, or vice versa, through the shared nerve pathways at a given spinal level.⁴ Whether this framework fully explains what clinicians observe remains debated, but it provides the rationale for why DOs might use manual techniques to address conditions that seem, at first glance, unrelated to the musculoskeletal system.

In practice, the vast majority of DOs work in conventional medical settings, and many rarely use OMT at all. Primary care DOs are the most likely to incorporate it into their practice; surgeons and hospital-based specialists generally do not. The amount of OMT a patient receives depends heavily on the individual physician’s practice style.

Does OMT Actually Work?

The condition with the strongest evidence base for OMT is low back pain. A meta-analysis of randomized controlled trials found that OMT produced a statistically significant reduction in low back pain, with pain decreasing compared to both active treatment, placebo controls, and no-treatment controls. Those benefits held across short-term, intermediate, and long-term follow-up periods.⁵ A later systematic review and meta-analysis confirmed that moderate-quality evidence supports OMT for both pain relief and improved physical function in acute and chronic nonspecific low back pain.⁶

That said, the picture is more complicated than “it works.” One well-designed randomized trial compared OMT, sham manipulation (where the therapist goes through motions without applying therapeutic force), and no treatment at all. Both the real OMT group and the sham group improved more than the no-treatment group, but OMT did not significantly outperform sham manipulation.⁷ That finding raises a familiar question in manual therapy research: how much of the benefit comes from the specific technique, and how much comes from the therapeutic encounter itself, including physical touch, time spent with a practitioner, and the expectation of improvement?

Beyond back pain, evidence is thinner. A pilot study in children with acute ear infections found that adding OMT to standard care led to faster clearing of middle ear fluid compared to standard care alone.⁸ But a broader scoping review of OMT for pediatric ear infections concluded that the existing literature suggests only modest potential benefits and is limited in both scope and quality, with larger and more rigorous trials needed before firm conclusions can be drawn.⁹ For most other conditions, evidence is either preliminary or absent. This is worth understanding not as a strike against DOs, but as context: OMT is one tool in a DO’s toolkit, and most of a DO’s clinical work relies on the same evidence-based pharmacological, procedural, and surgical interventions used by MDs.

The Residency Merger and What It Changed

For most of modern American medical history, DOs and MDs trained in separate residency systems. MD residencies were accredited by the Accreditation Council for Graduate Medical Education (ACGME), while DO residencies had their own accrediting body (AOA). In 2020, those two systems merged into a single accreditation system (SAS) under ACGME. The goal was straightforward: eliminate the parallel structures and create a unified graduate medical education system where DOs and MDs train side by side.

The merger was a milestone for integration, but it came with growing pains. The transition eliminated some residency positions that had been reserved specifically for DO graduates. In surgical specialties, osteopathic graduates in 2020 faced fewer DO-oriented ACGME programs while contending with the longstanding tendency of established ACGME surgical programs to favor graduates from allopathic medical schools.¹⁰ In ophthalmology, researchers found that the transition primarily harmed DO applicants: factors like the closure of osteopathic ophthalmology residency programs and the loss of protected positions contributed to a drop in osteopathic representation in the match.¹¹

The news is not uniformly negative, though. In otolaryngology (ear, nose, and throat surgery), osteopathic matches actually rose significantly after the merger, climbing from 17 in 2020 to 26 in 2024, while allopathic match numbers stayed stable. The researchers found a strong upward trend for DO candidates in that specialty with no evidence of MD candidates being displaced.¹² So the effects of unification have varied dramatically by specialty. In some fields, DOs have gained ground. In others, losing the protected positions that guaranteed a minimum number of osteopathic trainees has been a real setback.

Lingering Bias and the Perception Gap

One of the most persistent challenges facing osteopathic physicians has nothing to do with their clinical skills. It has to do with how people perceive them. A cross-sectional survey conducted in Fresno County found that 72% of community respondents were unaware of the distinction between osteopathic and allopathic medicine. When asked whether DOs receive training similar to MDs, 45% were neutral, meaning they simply did not know, and 17% actively disagreed.¹³ The knowledge gap is wide enough that many patients who see a DO may not fully understand what the letters after their doctor’s name mean.

The perception problem also exists within medicine itself. A study of pathology residency program leaders found that some negative perceptions of osteopathic physicians persist in the profession, on social media, and in nonscholarly publications. However, when those same program directors had actual experience training DO residents, their assessments were equivalent to those of allopathic residents, and they appeared to consider osteopathic applicants fairly equally.¹⁴ The pattern is familiar: secondhand impressions skew negative, but firsthand experience closes the gap. For DO students applying to competitive residencies, though, the secondhand impressions can still be a barrier at the application stage.

In the Exam Room, the Differences Fade

Whatever the philosophical and educational differences between DOs and MDs, patient visits look remarkably similar. A study that compared office visits between osteopathic and allopathic general and family medicine physicians using national data found no significant differences in time spent with patients, the provision of common preventive medicine counseling services, or the likelihood of a visit being focused on preventive care.¹⁵ If you walked into two different family medicine offices, one staffed by a DO and one by an MD, you would likely have trouble telling the difference based on the visit alone.

This is not a failure of osteopathic identity. It reflects the reality that the two professions converged over the course of a century. DOs prescribe the same medications, order the same imaging, and follow the same clinical guidelines. The added osteopathic perspective may subtly shape how a DO approaches a patient, perhaps paying more attention to musculoskeletal contributions to a complaint or being more willing to incorporate manual techniques, but the vast majority of clinical decisions are identical.

DO Growth and Why It Matters for Patients

Osteopathic medicine is one of the fastest-growing sectors of American medical education. The number of osteopathic medical schools has expanded significantly over the past two decades, and DOs now make up a growing share of the physician workforce. In orthopedic surgery alone, the number of osteopathic residents graduating each year increased by about a third over the past decade, with forecasts predicting continued growth.¹⁶

For you as a patient, this expansion means you are increasingly likely to encounter a DO, especially in primary care, where osteopathic physicians have historically been concentrated. It also means the question of “should I see a DO or an MD” is becoming less meaningful with each passing year. Both hold unrestricted medical licenses. Both complete accredited residencies. Both are board-certified in their specialties. The credential after the name tells you something about where and how the physician was trained, but it tells you very little about the quality of care you will receive.

When the DO Distinction Might Matter to You

There are a few situations where the DO-versus-MD distinction could actually be relevant to your care decisions. If you are dealing with chronic musculoskeletal pain, particularly low back pain, and you are interested in a hands-on approach as part of your treatment plan, a DO who actively uses OMT may offer something an MD typically would not. You would want to ask directly: not all DOs incorporate OMT into their practice, and those who do vary widely in how much they rely on it.

If you have strong preferences about a holistic or whole-body philosophy of care, you may find that a DO’s training aligns with what you are looking for. But that is a tendency, not a guarantee. Plenty of MDs practice holistically, and plenty of DOs practice in highly specialized, procedure-focused ways that look nothing like the osteopathic tradition.

If you are a medical student choosing between a DO and an MD program, the calculus is more complicated. Both paths lead to full physician licensure. But the residency match data shows that in certain competitive specialties, DO graduates still face headwinds that their MD peers do not. Those headwinds are diminishing in some fields and persisting in others. The single accreditation merger removed formal barriers but did not instantly erase informal preferences. For students aiming at the most competitive surgical or procedural specialties, this is a practical consideration worth researching at the program level.

Osteopathic Medicine Outside the United States

One area of frequent confusion is how “osteopath” means something quite different outside the United States. In most other countries, osteopaths are not physicians. They are manual therapy practitioners, somewhat analogous to chiropractors or physiotherapists, who use hands-on techniques but cannot prescribe medication or perform surgery. The American DO degree is unique in producing physicians who carry the full scope of medical practice alongside osteopathic manual training.

This distinction matters if you encounter an osteopath while traveling or read about osteopathy in an international context. A British or Australian osteopath has completed a very different educational program than an American DO. They may be highly skilled in manual therapy, but they are not trained as full-spectrum physicians. When research on osteopathic techniques comes from outside the United States, it is often conducted by these non-physician osteopaths, which complicates efforts to generalize findings to the DO physician context. The shared name creates an identity problem that the osteopathic profession in the United States has grappled with for decades, and it contributes to some of the public confusion about what a DO actually is.