Kevin Lutz, MD, FACP
Jun 1 2021

MD, DO, NP, PA…What do all these letters signify?


Medical Training

What is the difference between MD and DO?

You might be surprised to learn there is more in common than you might think. After completing four years of college (with an average GPA of 3.6), both types of students enter rigorous training in a four-year medical school. Both must pass a three-part licensing exam during their training. Both study all the basic sciences of medicine including anatomy, physiology, embryology, biochemistry, microbiology, pathology, statistics . . . and on and on. DO students also complete 200 hours of study on the musculoskeletal system called osteopathic manipulative treatment. Both types of medical students spend their 3rd and 4th years training in all the different fields of medicine including Internal Medicine, Pediatrics, Surgery, Psychiatry, Cardiology, Pulmonology, Emergency Medicine, Orthopedics, Nephrology, Family Medicine...and on and on.

After completing their medical school training, these graduates become doctors. However, they are still not done training! They then attend a residency in their chosen field. MD’s & DO’s train side by side with no differentiation between the two. After residency (a minimum of three more years of education and training while directly caring for patients), they are fully-licensed doctors ready to finally start their careers. Those going into subspecialties like Cardiology, Pulmonology, and specialized areas of surgery will continue their training in a fellowship. In short, when a doctor walks in to take care of you, you can be assured you are in good hands whether their name is followed by DO or MD.

What is the difference between NP and PA?

Often referred to as mid-level providers, both Nurse Practitioners (NP) and Physician Assistants (PA) are highly trained medical professionals. Students considering an advanced career in healthcare but who do not want to go to medical school often turn to these options. The biggest difference between the two is the training model from which the students learn. Physician assistants train using the medical model similar to physicians. The focus of their training is on the testing, diagnosis, and treatment of disease. PA’s tend to look first at the pathology of the problem and then how to cure it. In contrast, nurse practitioners train in the nursing model and focus on the patient in need of testing, diagnosis and treatment. It is a subtle but important difference. NP students learn to assess how illness affects the quality of a patient’s life and how racial, ethnic, and cultural beliefs or socioeconomic status impacts patients’ lives and health. Both healthcare providers spend three to four years after college earning their advanced degrees.

PA’s train as generalists, which means that after graduation they can practice in almost any field within medicine. This general medicine focus means they can switch specialties throughout their career without the need for re-certification. NP training programs include a concentration on a specific patient population. Areas of specialty include acute care, adult, family, gerontology, neonatology, oncology, pediatrics, or women’s health. In Colorado, NP’s can work independently while PA’s require a supervising physician. PA’s and NP’s work in hospitals, clinics, and physicians’ offices. They fill similar roles within any given setting. They are both licensed and skilled professionals who often provide the same medical care as physicians.

My patients often ask whom they should schedule appointments with when going to see other medical specialties. My answer is “schedule with whomever can see you first.” If you see a mid-level provider, be assured there is an MD or DO not far away who will also be included in your medical care.

As a faculty member at both the University of Colorado School of Medicine (an MD program) and the Kansas City University of Medicine and Biosciences (a DO program), I regularly train medical students in my office. Being a part of their education is a privilege and a joy!