Physician Assistants

Reviewed by Ann Dietrich, MD, FAAP, FACEP 

Key Takeaways

Physician assistants, more commonly referred to as PAs, are licensed clinicians who practice medicine in every specialty and setting in the United States. They are educated at the master’s degree level through accredited PA programs, must pass the Physician Assistant National Certifying Examination for initial certification, and are licensed at the state level. In practice, PAs examine patients, diagnose illness, order and interpret tests, develop treatment plans, prescribe medications within state law, and assist in procedures or surgery, typically as part of a physician-led or physician-collaborative care model.  

For clinicians, the most important distinction between PAs and nurse practitioners (NPs) is not simply “what they can do,” but how they are trained: PA education follows a generalist medical model, while NP education is rooted in advanced nursing. Terminology is also in transition. The national PA professional society now uses “physician associate,” but “physician assistant” remains the legal and regulatory term in most settings, so both terms are in active use.  

Introduction

For a clinician audience, the PA profession is best understood as a mature, nationally regulated advanced practice profession that was designed to expand access to medical care through team-based practice. The American Academy of Physician Associates (AAPA) states that PAs are licensed clinicians who practice medicine in every specialty and setting, while the Bureau of Labor Statistics describes them as clinicians who examine, diagnose, and treat patients under physician supervision. Those two descriptions capture the profession’s current identity: medically trained, broadly deployable, and embedded in physician-led or physician-linked systems of care — with the details of practice shaped by state law and local practice agreements.  

What is a physician assistant?

A PA is a licensed medical professional trained to evaluate patients, make diagnoses, order and interpret tests, initiate treatment, prescribe medications where authorized, counsel patients, and assist with procedures and surgery. AAPA describes PAs as medical professionals who diagnose illness, develop and manage treatment plans, prescribe medications, and often serve as a patient’s principal healthcare provider. The Bureau of Labor Statistics (BLS) similarly notes that PAs examine, diagnose, and treat patients and work in physicians’ offices, hospitals, outpatient clinics, and other healthcare settings.  

One useful way to explain the profession to clinicians is that PAs are not “mini-physicians,” nor are they a nursing role. They are a distinct licensed profession educated in a medical model designed to prepare them for broad clinical practice, with later specialization typically occurring on the job rather than through profession-specific residency requirements. Accreditation Review Commission on Education for the Physician Assistant (ARC-PA) standards emphasize a common core curriculum with sufficient breadth and depth to prepare graduates for practice, which aligns with the profession’s generalist foundation.  

What do physician assistants do?

In day-to-day care, PAs take histories, perform physical examinations, formulate differential diagnoses, order laboratory and imaging studies, interpret results, create treatment plans, prescribe medications as permitted by state law, perform procedures, and provide patient education and follow-up. AAPA’s scope materials describe this broad clinical role explicitly, and BLS notes that PAs provide healthcare services typically performed by physicians, including complete physicals, treatment, counseling, and in some cases prescribing medication.  

The practical scope of a PA depends on specialty, employer, physician relationship, and state law. AAPA’s state law resources make clear that prescribing authority, practice agreements, and regulatory terminology vary by jurisdiction, even though the core clinical skill set is nationally recognizable. That is why two PAs with similar education may have somewhat different operational scope depending on whether they work in emergency medicine, orthopedics, hospital medicine, oncology, or a rural primary care setting.  

How to become a physician assistant

The standard pathway begins with completion of prerequisite undergraduate coursework and admission to an accredited PA program. BLS states that physician assistants typically need a master’s degree from an accredited program, and ARC-PA is the accrediting body responsible for entry-level PA educational programs in the United States. ARC-PA currently lists more than 300 accredited PA programs.  

After graduation from an accredited PA program, candidates must pass the Physician Assistant National Certifying Examination, or PANCE, through the National Commission on Certification of Physician Assistants (NCCPA). NCCPA states that graduating from an accredited PA program and passing PANCE are the core steps for initial certification, and that certification is a professional requirement for licensure in all U.S. states.  

Certification does not end after initial licensure. NCCPA’s current maintenance process spans a 10-year cycle, during which certified PAs must complete 100 CME credits in each two-year cycle and complete a recertification assessment through the Physician Assistant National Recertifying Examination (PANRE) or the Physician Assistant National Recertifying Examination Longitudinal Assessment (PANRE-LA) before the end of the certification cycle. For clinicians unfamiliar with the profession, this is an important point: PA practice is tied not only to initial training, but also to ongoing national certification requirements.  

What PA education looks like

PA education is built around a generalist medical curriculum. AAPA states that PAs are educated at the master’s degree level, and its profession materials note that PA training includes thousands of hours of medical education. ARC-PA standards require a broad curriculum in the medical sciences and supervised clinical practice experiences, reflecting the profession’s intent to prepare graduates for practice across settings rather than locking them into a single population track from the start.  

That generalist structure matters in workforce terms. A PA trained in a broadly medical model may begin in one field and later move into another specialty with employer-based onboarding and specialty-specific supervision. This flexibility has been one of the profession’s defining operational advantages in health systems facing staffing shortages, service line growth, and geographic maldistribution of clinicians.  

Nurse practitioners vs. physician assistants

The comparison between nurse practitioners and PAs is often oversimplified. Both are advanced clinicians who diagnose and treat patients, prescribe in most jurisdictions, and work across primary and specialty care. The more meaningful distinction is educational lineage and regulatory model. PAs are trained in a medical model through PA programs accredited by ARC-PA, whereas NPs are advanced practice registered nurses whose education is grounded in nursing and whose professional organization describes them as licensed, independent practitioners who practice autonomously and in coordination with other healthcare professionals.  

AANP’s scope statements emphasize that NPs diagnose and manage acute, chronic, and complex conditions and may practice autonomously depending on state law. By contrast, BLS and AAPA continue to describe PAs in relation to physician supervision or collaboration, though the exact legal language varies by state and continues to evolve. For clinicians, the operational takeaway is that NP autonomy is more directly tied to state Advanced Practice Register Nurse practice law, while PA practice more often remains structured through physician-linked practice frameworks, even as those frameworks are modernized.  

There is also a difference in how specialization is built. NP preparation usually begins with a population focus, such as family, adult-gerontology, pediatrics, or psychiatric-mental health. PA education, by contrast, is broad and generalist at entry, with specialty differentiation typically occurring after graduation in the workplace. That does not make one inherently superior to the other. Instead, it means the professions arrive at similar clinical functions through different training architectures. AANP’s education materials and ARC-PA’s accreditation framework support that distinction.  

Physician associate vs. physician assistant

This is one of the most important terminology questions in the profession right now. AAPA, which renamed itself the American Academy of Physician Associates, states that its House of Delegates affirmed “physician associate” as the official title of the PA profession in 2021 and that the organization is working to advance the title change nationally. At the same time, the profession still widely uses “PA,” and many official systems, statutes, employers, payers, and federal resources continue to use “physician assistant.”  

In practical terms, “physician associate” reflects the profession’s preferred branding direction, while “physician assistant” remains the legal or operational term in much of the country. AAPA’s own materials acknowledge ongoing state-by-state legislative work, and its June 2025 update reported that New Hampshire had become the third state to enact the title change officially. For a clinician readership, the safest wording is often “PAs (physician assistants/physician associates),” especially in educational content intended for a broad national audience.  

What clinicians should know

The clinically relevant point is that PAs are not an experimental workforce fix or a narrow extender role. They are licensed medical professionals with standardized national certification, accredited graduate education, and broad deployment across outpatient, inpatient, procedural, and surgical settings. AAPA estimates the profession includes nearly 190,000 PAs across all medical and surgical specialties, and BLS continues to classify the field as a distinct healthcare profession with nationwide licensure requirements.  

Clinicians should also understand that day-to-day PA utilization is heavily shaped by organizational design. Health systems that clearly define onboarding, supervision or collaboration pathways, specialty training expectations, prescribing processes, and escalation norms generally use PAs more effectively than organizations that reduce the role to generic support labor.  

Clinical bottom line

PAs are licensed clinicians educated in a generalist medical model who diagnose, treat, prescribe, and manage patients across specialties as part of team-based medical practice. Becoming a PA requires graduation from an accredited master’s-level program, passage of PANCE, state licensure, and ongoing certification maintenance through NCCPA. Compared with nurse practitioners, PAs often perform similar clinical functions but come from a different educational and regulatory pathway. And while “physician associate” is the profession’s preferred emerging title, “physician assistant” remains the term most clinicians will still encounter in statutes, job descriptions, and federal occupational resources.  

Frequently asked questions

What is a physician assistant?

A physician assistant, or PA, is a licensed clinician who practices medicine in every specialty and setting, including hospitals, clinics, and surgical services. PAs evaluate patients, diagnose disease, order tests, develop treatment plans, prescribe medications where authorized, and provide follow-up care.  

How do you become a physician assistant?

The usual path is graduation from an accredited PA program at the master’s degree level, passage of the Physician Assistant National Certifying Examination (PANCE) exam, and state licensure. Ongoing certification maintenance through the National Commission on Certification of Physician Assistants (NCCPA) is also required.  

What do physician assistants do?

PAs take histories, perform physical exams, order and interpret tests, diagnose illness, create management plans, prescribe medication, counsel patients, and in many settings assist in procedures or surgery.  

Are physician assistants the same as nurse practitioners?

No. PAs and nurse practitioners (NPs) may overlap substantially in clinical work, but their educational models differ. PA education follows a generalist medical model, while NP education is rooted in advanced nursing and population-focused Advanced Practice Registered Nurse preparation.  

What is the difference between physician associate and physician assistant?

“Physician associate” is the newer title endorsed by American Academy of Physician Associates, while “physician assistant” remains the term still used in many laws, institutions, and federal resources. In most real-world settings today, both refer to the PA profession.  

Are PAs licensed in every state?

Yes. The Bureau of Labor Statistics states that all states require physician assistants to be licensed. State laws differ, however, on practice details such as prescribing and the structure of physician collaboration or supervision.  

Do PAs have to maintain certification?

Yes. NCCPA’s current process requires ongoing CME across repeated two-year cycles and a recertification assessment during the 10-year certification maintenance cycle.  

Can PAs specialize?

Yes. PAs work in primary care and across medical and surgical specialties, including emergency medicine, surgery, psychiatry, and many others. Their education is generalist, and specialization commonly occurs through employment, supervised practice, and specialty-specific experience after graduation.