Medical credentials and degrees explained

If you're like most people, you see a variety of health care professionals. And you're probably familiar with common degrees, such as M.D. for doctor of medicine, but what about the other letters in the alphabet soup of health care?

Below you'll find the qualifications (also called credentials) and educational requirements for the professionals you're most likely to encounter in private practices, hospitals and other health care facilities. Most have at least a master's degree or more advanced education and training. Licensing requirements and specific services vary according to training, specialty and state law.


Doctors have the most demanding education and training requirements. They typically need a bachelor's degree followed by a degree from a four-year medical school and, depending on their specialty, three to seven years of additional training.

Credentials for doctors:

  • M.D.: Doctor of medicine
  • D.O.: Doctor of osteopathic medicine; equivalent to an M.D.
  • M.B.B.S.: Bachelor of medicine, bachelor of surgery; an international medical degree equivalent to an M.D. in the U.S. system (also abbreviated as M.B., Ch.B.; M.B., B.Ch.; M.B., B.Chir.)

Not every provider with a doctorate degree is a medical doctor. For example, optometrists and pharmacists have graduate degrees and specialized training but don't attend medical school.


Registered nurses usually take one of three education paths: a bachelor's degree in nursing, an associate degree in nursing or a diploma from a nursing program. Registered nurses shouldn't be confused with licensed practical nurses. Licensed practical nurses undergo less training (generally a one-year nursing program) and work under the direction of doctors and registered nurses.

Nurse practitioners, nurse-midwives and nurse anesthetists, also referred to as advanced practice registered nurses, must earn at least a master's degree.

Credentials for nurses:

  • R.N.: Registered nurse
  • N.P.: Nurse practitioner
  • A.P.N.P.: Advanced practice nurse practitioner (also abbreviated as A.P.N.)
  • A.P.R.N.: Advanced practice registered nurse (also abbreviated as A.P.R.)
  • C.N.M.: Certified nurse-midwife
  • C.N.P.: Certified nurse practitioner (also abbreviated as N.P.-C. or N.P.B.C.)
  • C.R.N.A.: Certified registered nurse anesthetist
  • D.N.P.: Doctor of nursing practice
  • L.P.N.: Licensed practical nurse

Physician assistants

Physician assistants are sometimes confused with nurse practitioners. While their roles can be similar, there are key differences. Physician assistants typically need a master's degree. Although their duties are determined by their supervising doctor and state law, physician assistants provide many of the same services as a primary care doctor.

Credentials for physician assistants:

  • P.A.: Physician assistant
  • P.A.-C.: Certified physician assistant

When in doubt, ask

Of course, this list doesn't include all of the health care professionals you may encounter. So if you see credentials that are new to you, don't be afraid to ask for a quick explanation.

Last Updated May 10, 2019

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