A physician assistant’s scope of practice covers diagnosing illness, ordering and interpreting tests, developing treatment plans, performing procedures, assisting in surgery, and prescribing medications in all 50 states. What varies, and what matters most for any individual PA, is the legal relationship with a physician that the state requires, the hospital or employer’s credentialing decisions, and the federal rules that apply to controlled-substance prescribing. Two PAs with identical training can carry meaningfully different authority depending on where they practice.
What PAs Are Trained and Licensed to Do
PAs are educated as generalists and then narrow their focus through clinical experience and employer-specific credentialing. In day-to-day practice they perform comprehensive physical exams, diagnose conditions, order and interpret labs and imaging, write treatment plans, and assist in surgery.1National Conference of State Legislatures. Physician Assistant Practice and Prescriptive Authority That list covers the core of what most physicians do.
In surgical settings, PAs commonly serve as first assistants during operations, handling tissue, managing sutures, and providing technical support to the lead surgeon. They also run pre-operative preparation and post-operative recovery. In primary care and outpatient settings, PAs often function as the main provider for a given patient: managing chronic conditions like diabetes and hypertension, performing minor procedures such as suturing lacerations and administering injections, adjusting medications, interpreting lab trends, and referring to specialists when needed.
Prescribing Authority
PAs can prescribe medications in all 50 states, the District of Columbia, and most U.S. territories. For non-controlled drugs like antibiotics or blood pressure medications, writing a prescription is straightforward.
Controlled substances require registration with the Drug Enforcement Administration, which currently costs $888 for a three-year cycle.2Federal Register. Registration and Reregistration Fees for Controlled Substance and List I Chemical Registrants The federal scheduling system runs from Schedule II (highest abuse potential among prescribable drugs, including medications like oxycodone and methylphenidate) through Schedule V. Federal law prohibits refills on any Schedule II prescription; a new prescription is required each time.3GovInfo. 21 USC 829 – Prescriptions A practitioner may issue multiple Schedule II prescriptions at once to cover up to a 90-day supply, but each one must include the earliest date the pharmacy may fill it.4eCFR. 21 CFR Part 1306 – Prescriptions Schedule III through V medications carry fewer restrictions.
Violations of the Controlled Substances Act can bring civil penalties and, more consequentially for a practicing PA, suspension or revocation of DEA registration.5Office of the Law Revision Counsel. 21 USC 842 – Prohibited Acts B Losing the DEA number ends the ability to prescribe controlled substances.
Telehealth and Controlled Substances
Federal law generally requires an in-person medical evaluation before prescribing a controlled substance. The DEA and HHS have extended the pandemic-era waiver of that requirement through December 31, 2026.6Federal Register. Fourth Temporary Extension of COVID-19 Telemedicine Flexibilities for Prescription of Controlled Medications During the extension, a DEA-registered PA can prescribe Schedule II through V controlled substances by telehealth without a prior in-person visit, as long as the prescription serves a legitimate medical purpose and the encounter uses real-time audio-visual communication. Whether this becomes permanent or expires is worth tracking if your practice relies on it.
Supervision, Collaboration, or No Required Relationship
The single biggest variable in PA practice is the legal relationship the state requires between a PA and a physician. Terminology varies: states use “supervision,” “collaboration,” “practice agreement,” or require no relationship at all, and labels don’t always track the practical meaning.
Direct supervision in the old sense (a physician physically present during patient care) has largely been replaced by broader arrangements. Most states now allow the supervising or collaborating physician to be available by phone or other electronic communication rather than on-site.1National Conference of State Legislatures. Physician Assistant Practice and Prescriptive Authority That shift is what lets PAs staff rural clinics, urgent care centers, and satellite offices miles from the collaborating physician.
Where a formal relationship is required, a written practice agreement typically spells out the PA’s specific duties, how physician consultation works for complex cases, how often charts are reviewed, and what level of on-site oversight is expected. Oversight often scales with experience: a new graduate may face more chart review and consultation requirements than a PA with 15 years in the same specialty. Operating outside the terms of the agreement exposes the PA to disciplinary action and potential malpractice liability.
Six states have eliminated the mandatory physician-PA practice relationship entirely: Iowa, Montana, New Hampshire, North Dakota, Utah, and Wyoming. In those states, PAs can practice without a supervision or collaboration agreement, consistent with the professional model called Optimal Team Practice. In the states that still require a formal physician relationship, the terminology is gradually shifting from “supervision” to “collaboration” or “practice agreement.” Even where no relationship is legally required, PAs routinely consult with physicians on complex cases; the difference is whether consultation is driven by statute or by clinical judgment.
Hospital Credentialing as a Second Limit
A state license sets the outer boundary of what a PA can do, but hospitals and health systems impose a second layer through credentialing and privileging. Before a PA can work in a facility, the institution verifies licensure, national certification, and graduation from an accredited program. Specific clinical privileges are then granted based on documented experience, peer review, recommendations from collaborating physicians, and continuing education.
Specialized or high-risk work draws extra scrutiny. A PA requesting privileges in interventional cardiology or neurosurgery may need to show specialized training, document a minimum number of procedures performed, and complete a period of direct proctoring before practicing independently within the facility. Re-privileging follows a similar pattern. The result is that a PA’s day-to-day scope inside a hospital is often narrower than what the state license technically allows.
Billing Rules That Shape Scope in Practice
How PA services get paid for shapes how PAs are used. Under Medicare, PA services are reimbursed at 85% of the physician fee schedule when the PA bills directly under their own National Provider Identifier.7Centers for Medicare & Medicaid Services. Incident To Services and Supplies Every PA who bills Medicare or other insurers needs an NPI, the unique 10-digit identifier required under HIPAA.8Centers for Medicare & Medicaid Services. National Provider Identifier Standard (NPI)
Medicare also allows “incident-to” billing, where services provided by a PA are billed under the supervising physician’s name and reimbursed at 100% of the fee schedule. The conditions are strict: the physician must have performed the initial service and remain actively involved in the patient’s care, the PA must work under the physician’s direct supervision (meaning the physician is in the office suite), and the services must be provided in an office or clinic setting.7Centers for Medicare & Medicaid Services. Incident To Services and Supplies Any state-mandated supervisory or collaborative relationship satisfies Medicare’s supervision requirement.9eCFR. 42 CFR 410.74 – Physician Assistants’ Services
The 15% gap between direct billing and incident-to billing creates real tension. Some employers push PAs toward incident-to arrangements to maximize revenue, even when the supervision requirements are hard to meet consistently. If the collaborating physician isn’t actually in the office suite, incident-to billing is a compliance risk.
Keeping the License and Certification Active
PAs are regulated at the state level by boards of medicine, dedicated physician assistant boards, or composite health licensing boards.10American Academy of Physician Associates. List of Licensing Boards Initial licensure requires passing the Physician Assistant National Certifying Exam (PANCE), administered by the National Commission on Certification of Physician Assistants. The PANCE fee is $550, with separate state application fees on top.11NCCPA. Become Certified
NCCPA certification runs on a 10-year cycle broken into five two-year periods. Each two-year period requires 100 hours of continuing medical education. By the end of the 10 years, a PA must pass either the traditional proctored PANRE or the PANRE Longitudinal Assessment, each costing $350.12NCCPA. Maintain Certification13NCCPA. PANRE Longitudinal Assessment Fact Sheet Letting certification lapse means losing the ability to practice in most states.
State boards also set the specific scope of practice within their jurisdiction, enforce CME requirements, investigate complaints, and discipline misconduct. Sanctions range from reprimands and required training to suspension or permanent revocation. PAs who hold licenses in more than one state need to track each state’s rules separately; assumptions carried across state lines are a common source of compliance trouble.
Liability Exposure
PAs carry their own malpractice exposure, but the picture is more complicated than for a physician practicing independently. When a PA causes harm, the supervising or collaborating physician may be held vicariously liable by virtue of the supervisory relationship, even if the physician wasn’t present and had no direct involvement in the specific decision.
Most PAs are covered by an employer’s malpractice policy, and many also carry individual coverage. Two policy types dominate:
- Occurrence policies cover any incident that happens during the policy period, regardless of when the claim is filed. If a patient sues three years after the policy expires, events that occurred while the policy was active are still covered. No tail coverage is needed at job changes or retirement, but premiums tend to be higher upfront.
- Claims-made policies cover only claims filed while the policy is in force. If the policy lapses before a claim is filed, there is no coverage unless the PA buys tail coverage to extend the reporting window, or secures prior-acts (nose) coverage from the next insurer. Premiums start lower and increase over several years to a mature rate.
The distinction matters most at career transitions. A PA leaving a practice with a claims-made policy who doesn’t line up tail or nose coverage has a gap that can become personally expensive if a claim surfaces later.