Understanding Medical Credentials: MD, DO, NP, PA, and More
February 7, 2026
Walking into a doctor's office, you'll notice credentials listed after provider names. MD, DO, NP, PA, CRNA — what do they all mean? Understanding the differences helps you know who you're seeing and what kind of training they've had.
MD — Doctor of Medicine
An MD is a physician who completed four years of medical school at an allopathic (traditional Western medicine) institution, followed by a residency of 3-7 years depending on specialty. MDs make up the majority of physicians in the United States. You'll find them across all specialties on DoctorDataHub — for example, browsing internal medicine or orthopedic surgery.
DO — Doctor of Osteopathic Medicine
A DO undergoes training very similar to an MD, but at an osteopathic medical school with additional coursework in osteopathic manipulative medicine. DOs are fully licensed physicians in all 50 states and can practice in any specialty. In practical terms, MD and DO are equivalent for most patient care purposes.
NP — Nurse Practitioner
Nurse practitioners hold a graduate nursing degree (MSN or DNP) and are licensed to diagnose, treat, and prescribe medication — either independently or collaboratively depending on state law. NPs often serve as primary care providers, particularly in underserved areas.
PA — Physician Assistant
Physician assistants complete a master's-level clinical program and are licensed to practice medicine under physician supervision (though scope varies by state). PAs work across virtually every medical specialty.
All of these provider types are registered in NPPES and searchable on DoctorDataHub. Use the search page or browse by specialty to find any credential type.