MDs and DOs are both fully licensed physicians who can practice in every medical specialty, prescribe medications, and perform surgery in all 50 states. The core difference is their training philosophy: MD programs follow allopathic medicine, while DO programs follow osteopathic medicine, which places extra emphasis on the body’s musculoskeletal system and its connection to overall health. In practical terms, the two degrees lead to the same career options, and the distinction matters less today than it did even a decade ago.
How the Training Compares
The structure of MD and DO programs is nearly identical. Both require four years of medical school, with the first 12 to 24 months spent mostly in the classroom covering anatomy, pharmacology, pathology, and other foundational sciences. The remaining time is spent in clinical rotations, where students work directly with patients in hospitals and clinics.
The key curricular difference is that DO students also learn osteopathic manipulative treatment, or OMT. This is a set of hands-on techniques used to diagnose and treat musculoskeletal problems and, in some cases, other conditions. Techniques include muscle energy (where the patient actively contracts muscles against resistance), myofascial release, counterstrain, and high-velocity thrust maneuvers similar to what you might associate with chiropractic care. This training gives DO students additional coursework focused on the musculoskeletal system that MD students don’t receive.
The Osteopathic Philosophy
DO programs are built around four guiding principles that shape how osteopathic physicians are taught to think about patient care. The first is that the body is a unit of body, mind, and spirit, not a collection of separate organ systems. The second is that the body is capable of self-regulation and self-healing. The third is that structure and function are connected: the way the body is physically built affects how it works, and vice versa. The fourth is that treatment should be guided by all three of these ideas together.
In practice, this means DO training tends to emphasize a whole-person approach. That doesn’t mean MDs ignore the big picture or that DOs avoid specialization. It’s more of a framing difference in how students are taught to evaluate patients. Many DOs gravitate toward primary care, though they practice across all specialties.
Licensing Exams
MD graduates take the United States Medical Licensing Examination (USMLE), a three-step test required for medical licensure. DO graduates take the Comprehensive Osteopathic Medical Licensing Examination (COMLEX-USA), which serves the same purpose but also tests osteopathic principles and OMT knowledge. Many DO students choose to take both exams, particularly if they’re applying to competitive residency programs that historically used USMLE scores as a benchmark.
Residency Training Is Now Unified
This is one of the biggest recent changes in medical education. Until 2020, MD and DO graduates often trained in separate residency systems with different accreditation bodies. A five-year transition that began in 2015 merged everything under a single accreditation system run by the Accreditation Council for Graduate Medical Education (ACGME). That transition concluded in June 2020.
The result is that all U.S. medical school graduates, whether MD or DO, now compete for and complete residency in the same ACGME-accredited programs. They’re evaluated against the same milestones and competency standards. This change significantly leveled the playing field. During the transition period, filled residency positions in programs that had previously been accredited only through the osteopathic system grew by 22 percent, reaching over 10,400 positions by 2020.
Admissions Differences
MD programs are generally more competitive on paper. Matriculants at MD-granting schools in the 2023-2024 cycle had an average MCAT score of 511.7 and an average undergraduate GPA of 3.77. DO programs typically accept students with somewhat lower MCAT scores and GPAs, though their admissions have grown more competitive over time as the profession has expanded. Some applicants apply to both MD and DO programs to maximize their chances of getting into medical school.
The DO Profession Is Growing Fast
Osteopathic medicine now represents roughly 11 percent of all physicians in the United States and more than 25 percent of all medical students. About 40,000 osteopathic medical students are currently enrolled for the 2025-2026 academic year, and the total number of DOs and osteopathic medical students across the country has reached over 207,000. That growth reflects both an increase in new DO schools and expanding class sizes at existing ones.
International Recognition
Within the U.S., there is zero difference in how MDs and DOs are licensed or what they can do. Internationally, the picture is more uneven. DOs trained in the U.S. have full practice rights in more than 65 countries. However, in some countries the “DO” title is associated only with manual therapy (similar to how osteopaths are trained in parts of Europe and Australia), which can create confusion. U.S.-trained DOs are unique in being fully licensed physicians. If you’re a DO considering practicing abroad, checking country-specific licensing requirements in advance is important.
What This Means for Patients
If you’re choosing a doctor, the letters after their name matter far less than their training, experience, and specialty board certification. An MD and a DO who completed the same residency program and passed their boards have functionally identical qualifications. The DO may incorporate hands-on musculoskeletal techniques into their practice, which some patients find helpful for chronic pain, back problems, or headaches, but not every DO uses OMT regularly, especially those in surgical or hospital-based specialties.
If you’re deciding which type of medical school to attend, the practical differences come down to whether the osteopathic philosophy and OMT training appeal to you, how competitive your application is, and whether certain residency programs you’re interested in have any historical preferences. The single accreditation system has made that last factor increasingly irrelevant. Both paths lead to the same destination: a fully licensed physician who can practice any type of medicine.