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MD, DO, PA, NP and More: Understanding the Differences

There are many kinds of BCH health care professionals who can help you stay healthy. We have DOs, MDs, NPs and PAs, to name a few. But who are all these providers? And, what training do they have?

To understand what those letters mean, read an excerpt from Insider’s Guide to Quality, Affordable Healthcare — a book and accompanying website aimed at helping readers become knowledgeable and active health care consumers.

Physicians (MD and DO)

The term “physician” refers to two slightly different medical degrees: MD (doctor of medicine) or DO (doctor of osteopathic medicine). Their training is similar in that both go through four years of medical school, another three to seven years in a residency program, and perhaps additional training in a fellowship program.

The American Association of Colleges of Osteopathic Medicine (AACOM) describes two differences in their training[1]. There is an integrated Osteopathic Philosophy where DOs are trained to look at the whole person from their first days of medical school. In addition, osteopathic medical students take approximately 200 hours of training in the art of osteopathic manipulative medicine.

Registered Nurses (RN), Nurse Practitioners (NP) and Clinical Nurse Specialists (CNS)

Differences in their training are reflected in the health care services they provide, called “scope of practice.” Let’s start with registered nurses (RNs). The scope of practice of RNs includes:

  • Performing physical exams and obtaining health histories
  • Administering medications, wound care and numerous other personal interventions
  • Interpreting patient information and making decisions about needed actions
  • Directing and supervising care delivered by other health care professionals, such as licensed practical nurses (LPNs) and nurse aides

Nurse practitioners (NPs) begin as RNs who then take advanced training. Because NPs are also RNs, they can do all that RNs do plus provide additional services, which include:

  • Ordering, performing, and interpreting diagnostic tests such as lab work and X-rays
  • Diagnosing and treating acute and chronic conditions such as diabetes, high blood. pressure, infections and injuries
  • Prescribing medications and other treatments
  • Co-ordinating patients’ overall care (i.e., primary care function)
  • Counseling
  • Educating patients on disease prevention and positive health and lifestyle choices

Clinical Nurse Specialists (CNS) are registered nurses who have graduate level nurse training at the master’s or doctoral level. They are certified in a specialty of choice. They can prescribe medications if they apply for prescriptive authority in 39 states, but prescribing is not always required in their practice. They usually focus on education, research and consulting.

Physician Assistants (PA)

Their scope of practice includes:

  • Taking your medical history
  • Conducting physical exams
  • Diagnosing and treating illnesses
  • Ordering and interpreting tests
  • Developing treatment plans
  • Counseling on preventive care
  • Assisting in surgery
  • Writing prescriptions
  • Making rounds in hospitals and nursing homes

While NPs can work independently, PAs must work under the formal legal supervision of a physician. While the physician need not be physically present, it is imperative that the PA and supervising physician can be in contact with each other by telecommunication.

Medical Assistants (MA)

There is another medical position, Medical Assistant, which should not be confused with Physician Assistant. Their level of training and clinical skills is much less than that of a PA. However, their skill set is in strong demand in medical settings and it is good to be familiar with their role and competencies as you are likely to meet them. They are cross-trained to perform administrative and clinical duties. The typical range of clinical duties include:

  • Taking medical histories
  • Explaining treatment procedures to patients
  • Preparing patients for examination
  • Assisting the physician during exams
  • Collecting and preparing laboratory specimens
  • Performing basic laboratory tests
  • Instructing patients about medication and special diets
  • Preparing and administering medications as directed by a physician
  • Authorizing prescription refills as directed
  • Drawing blood
  • Taking electrocardiograms
  • Removing sutures and changing dressings

Primary Care Providers (PCP)

A PCP is a physician (MD or DO), an NP or a PA who acts as the principal point of contact for a patient in the health care system. There are two types of Primary Care Physicians — family medicine doctors (family practitioners) and internal medicine doctors (internists).

According to the American College of Physicians (ACP), “Internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness.” Family medicine doctors receive required training in pediatrics and obstetrics-gynecology that is not in the required curriculum for internists. The American Academy of Family Physicians (AAFP) indicates that “Because of their extensive training, family physicians are the only specialists qualified to treat most ailments and provide comprehensive health care for people of all ages – from newborns to seniors.”

Look for more insights from Insider’s Guide to Quality, Affordable Healthcare. For information about this book, visit

About the Authors

lawrence lazarusLawrence W. Lazarus, MD, has specialized in geriatric medicine and psychiatry at Rush Medical School and University in Chicago, Illinois, where he founded the Geriatric Psychiatry Fellowship Program. He is a former president of the American Association for Geriatric Psychiatry and was awarded numerous teaching and research grants from the National Institute of Mental Health. Dr. Lazarus is in private practice in Santa Fe, New Mexico.

jeffrey fosterJeffrey Foster, MD, has spent his clinical and academic career with Geriatric Psychiatry as a prominent focus. He has worked closely with primary care physicians, nurses, social workers and various specialists in hospital and outpatient settings. A former President of the American Association of Geriatric Psychiatry, Dr. Foster has received various teaching and research grants from the National Institute of Mental Health.