A PA, short for physician assistant (now increasingly called physician associate), is a licensed medical professional who diagnoses illnesses, develops treatment plans, and prescribes medications. PAs work across virtually every medical specialty, from family medicine to surgery to emergency care. The median annual salary for physician assistants was $133,260 in 2024, and employment is projected to grow 20 percent over the next decade, making it one of the fastest-growing healthcare professions in the country.
What PAs Actually Do
PAs practice medicine in much the same way physicians do on a day-to-day basis. They take patient histories, perform physical exams, order and interpret lab work and imaging, diagnose conditions, and create treatment plans. In most states, PAs also prescribe medications, including controlled substances. The key distinction is that PAs practice collaboratively with physicians rather than fully independently, though the degree of oversight varies significantly depending on the state and the clinical setting.
Unlike nurse practitioners, who are trained in an advanced nursing model with a chosen population focus (such as pediatrics or adult-gerontology), PAs are trained as medical generalists using a curriculum modeled directly on medical school. This generalist training means PAs can shift between specialties throughout their careers without going back to school. A PA working in orthopedic surgery could transition to dermatology or emergency medicine with on-the-job training in the new specialty.
Where PAs Work
The PA profession has shifted substantially away from primary care over the past two decades. In 1997, about 46 percent of PAs worked in primary care. By 2013, that number had dropped to roughly 28 percent. Over the same period, PAs working in adult medical specialties grew from 17 to 26 percent, and urgent care emerged as a significant employer, accounting for 10 percent of the PA workforce. A larger proportion of PAs now work in procedural specialties like surgery and emergency medicine compared to nurse practitioners, who remain more concentrated in general primary care settings.
You’ll encounter PAs in hospitals, outpatient clinics, urgent care centers, operating rooms, and rural health facilities. In surgical settings, PAs often serve as first assists during operations and manage patients before and after procedures. In emergency departments, they evaluate and treat everything from broken bones to chest pain. In primary care, they function much like a family doctor for routine visits, preventive screenings, and chronic disease management.
Education and Training
Becoming a PA requires completing a master’s degree program, typically lasting about 27 months. Most programs require applicants to already hold a bachelor’s degree and have direct patient care experience, often as an EMT, medical assistant, or similar role. PA programs are competitive, and many applicants have thousands of hours of healthcare experience before they’re admitted.
The curriculum mirrors a condensed version of medical school. The first year focuses on classroom and lab instruction in anatomy, pharmacology, pathophysiology, and clinical medicine. The second phase is entirely clinical. At UC San Diego’s program, for example, students complete 40 weeks of supervised clinical rotations across seven core areas: internal medicine, pediatrics, behavioral health, surgery, emergency medicine, women’s health, and additional medical or surgical disciplines. Students also complete elective rotations and a capstone research project. Each core rotation is four weeks of hands-on patient care in that specialty.
Certification and Licensing
After graduating, PAs must pass the Physician Assistant National Certifying Exam (PANCE) to become board certified and eligible for state licensure. Maintaining that certification is an ongoing process. Over each 10-year cycle, PAs must earn and log 100 continuing medical education credits every two years and pass a recertifying exam by the end of the 10th year. The recertifying exam can be taken as a single test or as a longitudinal assessment that begins in the seventh year of the cycle and spreads questions out over time. Every state requires PAs to hold current certification to practice.
How Much Oversight PAs Have
The level of independence a PA has depends heavily on state law. The American Academy of Physician Associates classifies state practice environments into four tiers: optimal, advanced, moderate, and reduced. In states with optimal practice environments, PAs have no legal requirement for a specific supervisory relationship with a physician. Their scope of practice, chart co-signature requirements, and proximity to a collaborating physician are all determined at the practice level, meaning the PA and their employer decide together what’s appropriate.
In more restrictive states, PAs may need a formal supervisory agreement with a named physician, on-site physician presence, mandatory chart reviews, or limits on how many PAs a single physician can oversee. The profession has been steadily moving toward greater autonomy, with the preferred terminology shifting from “supervision” to “collaboration” to better reflect how PAs actually function in modern healthcare teams.
The Name Change: Assistant to Associate
The profession is in the middle of a title transition from “physician assistant” to “physician associate.” The American Academy of Physician Associates (AAPA) has already adopted the new title across its own materials, and four states (Oregon, Maine, New Hampshire, and Iowa) have officially changed the title in state law. About a third of the profession’s constituent organizations have completed their own title change efforts so far. PAs in other states can use the “physician associate” title at their own discretion, though they’re encouraged to check their state’s specific laws before using it in clinical settings. The change reflects the profession’s argument that “assistant” understates the independent clinical judgment PAs exercise daily.
PA vs. Nurse Practitioner
PAs and nurse practitioners fill similar roles in healthcare, and patients often can’t tell the difference during a visit. The core distinction is educational philosophy. PA training follows a medical model, the same framework used to train physicians, with a generalist approach that doesn’t require choosing a specialty during school. NP training follows a nursing model, building on an existing nursing degree and requiring students to choose a population focus before starting their program.
In practice, this means PAs have more flexibility to switch specialties, while NPs tend to stay within their certified population focus. Both can diagnose, treat, and prescribe in most states, and both earn comparable salaries. The choice between seeing a PA or an NP for your care comes down more to the individual clinician’s experience and the specific practice than to any fundamental difference in what they’re allowed to do.