A PA, or physician assistant, is a licensed medical professional who holds an advanced degree and provides direct patient care. PAs diagnose illnesses, prescribe medications, order tests, and develop treatment plans, often working alongside physicians but frequently seeing patients on their own. The term “PA” can also refer to several medical concepts, but in everyday conversation, it almost always means this healthcare role.
What a PA Does Day to Day
PAs perform many of the same tasks as physicians. A typical day can include conducting patient exams, diagnosing conditions, ordering and interpreting lab work and imaging, prescribing medications, assisting in surgery, and counseling patients on preventive care. The breadth of what they handle is wide, from stitching a laceration in an emergency department to managing a patient’s diabetes over years in a primary care office.
The specific duties a PA can perform depend on state law and, in many states, a collaborative agreement with a supervising physician. Most PAs work independently within a defined scope of practice. Each state sets its own rules about which medications a PA can prescribe, for instance, and anything outside that list requires consultation with a physician. In practical terms, if you see a PA for a sinus infection, a sprained ankle, or a routine physical, your visit will look and feel very similar to seeing a doctor.
How PAs Are Trained
Becoming a PA requires a master’s degree from an accredited program. Most programs run about 27 months (three academic years), though some that include a pre-professional undergraduate phase can stretch to four to six years total. The curriculum is modeled on medical school training, covering the same core sciences and clinical skills but compressed into a shorter timeline.
Before applying, candidates typically need coursework in anatomy, physiology, biochemistry, microbiology, organic chemistry, genetics, psychology, and statistics, among other prerequisites. Once in the program, students complete more than 2,000 hours of clinical rotations across settings like ambulatory clinics, medical practices, and acute or long-term care facilities. The emphasis is on primary care, but rotations expose students to surgery, emergency medicine, pediatrics, and other specialties.
This generalist training is one of the defining features of the profession. Unlike nurse practitioners, who specialize in a chosen population focus (family, pediatrics, psychiatric/mental health, etc.), PAs are trained broadly and can shift between specialties throughout their careers without going back to school.
Certification and Ongoing Requirements
After graduating, PAs must pass a national certification exam before they can practice. To maintain certification, they earn 100 continuing medical education credits every two years, with at least 50 of those in formal, structured coursework. They also retake a recertification exam every 10 years. These requirements ensure PAs stay current with evolving medical standards throughout their careers.
How PAs Compare to Nurse Practitioners
PAs and nurse practitioners (NPs) fill similar roles in healthcare, and patients often can’t tell the difference during an appointment. The distinction is mainly in training philosophy and legal structure. PA programs follow a medical model, the same framework used to train physicians. NP programs are rooted in nursing, building on a foundation of registered nursing practice and focusing on a specific patient population.
On the supervision side, PAs nearly always work under some form of collaboration or supervisory agreement with a physician, though the degree of oversight varies widely by state. NPs have independent practice authority in more than 30 states. In day-to-day patient care, both can diagnose, treat, and prescribe, and in many clinics and hospitals you’ll see them working side by side doing essentially the same work.
Salary and Job Growth
The median annual salary for physician assistants was $133,260 as of May 2024, according to the Bureau of Labor Statistics. Employment in the profession is projected to grow 20 percent from 2024 to 2034, far outpacing the average for all occupations. That growth is driven by an aging population, expanding healthcare access, and the cost efficiency of using PAs to handle care that doesn’t require a physician’s level of training.
Other Meanings of “PA” in Medicine
If you came across “PA” in a medical context that doesn’t seem to involve a healthcare provider, it may refer to one of a few other things.
Pulmonary Artery
The pulmonary arteries carry blood from your heart to your lungs. They’re the only arteries in the body that transport oxygen-poor blood. Their job is to deliver blood to the lungs so it can pick up fresh oxygen and release carbon dioxide, then return to the heart for distribution to the rest of the body. You might see “PA” on an echocardiogram report or hear it mentioned during a discussion about heart or lung conditions.
Psoriatic Arthritis
Psoriatic arthritis (sometimes abbreviated PsA or PA) is a chronic inflammatory condition that causes joint pain, stiffness, and swelling, typically in people who also have the skin condition psoriasis. It can affect any joint in the body and often shows up as swollen, sausage-like fingers or toes, nail changes like pitting or crumbling, heel pain, or lower back stiffness. Fatigue and eye inflammation are also common. In rare, severe cases, it can cause significant damage to the small bones of the hands.
Pernicious Anemia
Pernicious anemia is an autoimmune condition that prevents the body from absorbing vitamin B12. Normally, a protein called intrinsic factor carries B12 from food through the small intestine and into the bloodstream, where it eventually reaches bone marrow to help produce red blood cells. In pernicious anemia, the immune system attacks intrinsic factor, blocking this entire chain. The result is a shortage of healthy red blood cells and the fatigue, weakness, and neurological symptoms that come with B12 deficiency.