DO stands for Doctor of Osteopathic Medicine. It’s a full medical degree, just like an MD (Doctor of Medicine), and physicians who hold it can practice in every medical specialty, prescribe medications, perform surgery, and do everything else an MD can do. About 8.5% of active physicians in the United States are DOs, and they hold full practice rights in more than 65 countries.
What DO Training Looks Like
Osteopathic medical school is a four-year program. The first two years focus on biomedical and clinical sciences, covering the same foundational material taught in MD programs: anatomy, physiology, pharmacology, pathology. The second two years shift to hands-on clinical training through required rotations in emergency medicine, family medicine, internal medicine, obstetrics and gynecology, pediatrics, psychiatry, and surgery.
One difference from MD programs is the clinical training model. DO students spend significant time in community hospitals and outpatient clinics, not just large academic medical centers. Many schools require a fourth-year rotation in a rural or underserved area. This reflects a long-standing emphasis in osteopathic education on primary care and community-based medicine, though DOs go on to specialize in everything from cardiology to neurosurgery.
How DOs Differ From MDs
The practical differences between an MD and a DO are smaller than most people assume. Both complete four years of medical school, pass national licensing exams, and train in the same residency programs. Since 2020, all residency programs in the U.S. operate under a single accreditation system, meaning MD and DO graduates train side by side and meet identical competency standards.
The philosophical difference is that osteopathic education frames the body as an interconnected system. Rather than treating a disease in isolation, DO training emphasizes how structure and function relate across the whole body. In practice, this translates to an additional curricular focus on the musculoskeletal system and a hands-on diagnostic skill set called osteopathic manipulative treatment, or OMT.
Osteopathic Manipulative Treatment
OMT is the most visible distinction in a DO’s training. It’s a hands-on technique where the physician uses gentle pressure, stretching, and resistance to manipulate muscles, soft tissues, and joints. The goal is to restore structural balance so that nerve and blood circulation improve to the affected area. Providers may use slow, continuous pressure or quick, targeted adjustments, though the thrust-based “popping” techniques are generally used less often than with a chiropractor.
Most people encounter OMT for lower back pain, neck pain, or migraines, but it’s used for a surprisingly wide range of conditions:
- Chronic pain: fibromyalgia, arthritis, carpal tunnel syndrome
- Breathing issues: asthma and sinus infections
- Digestive problems: irritable bowel syndrome and constipation
- Pregnancy-related discomfort: swelling, insomnia, sciatica
- Sports and repetitive stress injuries
Not every DO uses OMT in daily practice. A DO who specializes in cardiology or psychiatry may rarely perform it, while a DO in family medicine or sports medicine might use it regularly. It’s an additional tool in the toolkit, not a requirement of every patient visit.
Licensing and Board Exams
DO graduates take the Comprehensive Osteopathic Medical Licensing Examination (COMLEX-USA), a three-level exam sequence that tests both medical knowledge and clinical skills. Many DO students also choose to take the USMLE, which is the standard licensing exam for MD graduates, particularly if they’re applying to competitive residency programs. Both exams lead to the same outcome: a full, unrestricted medical license.
The Single Residency System
Until recently, MDs and DOs had separate residency accreditation systems. That changed with a major transition that began in 2015 and concluded in 2020. The Accreditation Council for Graduate Medical Education (ACGME) now oversees all residency and fellowship programs for both degree types. Ninety-eight percent of previously osteopathic-only programs that applied successfully transitioned to ACGME accreditation during this period.
This merger eliminated a practical barrier that had sometimes put DO graduates at a disadvantage when applying for residencies. Now, all U.S. medical school graduates compete for the same positions and are evaluated against the same specialty-specific milestones. Programs that want to preserve osteopathic training can apply for “Osteopathic Recognition,” a formal designation that integrates OMT education into the residency curriculum. The number of filled residency positions in formerly osteopathic-only programs grew 22% in the five years after the transition began.
Origins of Osteopathic Medicine
The osteopathic profession traces back to 1892, when a physician named Andrew Taylor Still founded the American School of Osteopathy in Kirksville, Missouri. Still believed that many diseases could be treated by finding and correcting structural problems in the body that interfered with circulation and nerve function. While the profession has evolved enormously since then, embracing modern pharmacology, surgery, and evidence-based medicine, that foundational emphasis on the musculoskeletal system and the body’s capacity to heal itself still runs through osteopathic education today.
What This Means if Your Doctor Is a DO
If you see “DO” after your doctor’s name, you’re seeing a fully licensed physician who completed the same length and rigor of training as an MD, passed national licensing exams, and finished an accredited residency. The care you receive will be functionally identical in most settings. The main difference is that your DO had additional training in hands-on musculoskeletal techniques and may take a slightly more whole-body approach to diagnosis and treatment. Whether that matters to you depends on what you’re being treated for, but it’s never a reason to question your doctor’s qualifications.