The short answer: in some states, very little separates what a doctor and nurse practitioner can do day to day. In others, the gap is significant. The differences come down to training depth, surgical authority, prescribing power, hospital roles, and how state law defines each provider’s scope of practice. Understanding where these lines fall helps you know what to expect from each type of provider.
The Training Gap
The most fundamental difference is how much supervised clinical experience each provider completes before practicing independently. Nurse practitioners accumulate 500 to 750 patient-care hours during their training programs, which typically last two to four years after becoming a registered nurse. Physicians complete four years of medical school followed by three to seven years of residency, logging between 12,000 and 16,000 patient-care hours before they’re done. That’s roughly 16 to 32 times more hands-on training.
Residency is where much of that gap forms. Physicians are required to complete residency in their chosen specialty before they can practice. Nurse practitioners have no residency requirement at all. Some voluntary NP residency programs exist, but they’re optional and relatively uncommon. This means a newly graduated NP may transition to independent practice with a fraction of the clinical exposure a physician had before ever seeing patients on their own.
Specialty training adds another layer. An AMA survey presented at the 2026 State Advocacy Summit found that one in three NPs and physician assistants switch specialties at least once during their careers, often without formal training in the new field. And data published by the American Association of Nurse Practitioners in 2024 showed that 92.8% of NPs lack any optional specialty certification beyond their base credential.
Surgical and Procedural Authority
Nurse practitioners can perform minor procedures: biopsies of skin lesions, wart removal, suturing lacerations, draining abscesses. What they cannot do is perform major or complex surgeries. Open-heart procedures, joint replacements, tumor resections, organ transplants, and other invasive operations are exclusively within the domain of physicians (specifically surgeons who completed surgical residencies and fellowships). No state grants NPs the authority to serve as the lead surgeon in an operating room for these procedures.
This distinction matters most in specialty and surgical care. If you need a procedure that involves general anesthesia, opening a body cavity, or operating on internal organs, a physician will be performing it. NPs may assist in the operating room or manage your pre- and post-surgical care, but the surgery itself falls outside their scope.
Prescribing Restrictions
In states with full practice authority, nurse practitioners can prescribe the same medications as physicians, including controlled substances. But in states with reduced or restricted practice laws, NPs face limits that physicians do not, particularly for Schedule II controlled substances like opioids, certain stimulants, and strong pain medications.
The restrictions vary widely and can be surprisingly specific. In Arkansas, NPs can prescribe Schedule II opioids only for a five-day supply or less, and they can prescribe stimulants only if a physician initially started the patient on them. Ohio is even more restrictive: NPs can prescribe Schedule II drugs only for terminally ill patients, only if a supervising physician wrote the original prescription, and only for a 24-hour supply. South Carolina caps NP opioid prescriptions at five days, West Virginia at three days, and Wisconsin prohibits NPs from prescribing Schedule II amphetamines entirely except for narrow conditions like cancer pain, narcolepsy, or epilepsy.
If you’re being treated for chronic pain, ADHD, or another condition requiring controlled substances, these limits could affect your care depending on where you live. A physician faces none of these state-level prescribing caps.
Hospital Admitting and Inpatient Oversight
Federal regulations from the Centers for Medicare and Medicaid Services allow nurse practitioners to admit patients to hospitals when state law permits it. But there’s a critical caveat: if a Medicare patient is admitted by a practitioner other than a physician, that patient must still be under the care of a doctor of medicine or osteopathy. Federal rules also require that a physician be responsible for the care of each Medicare patient regarding any medical or psychiatric problem present on admission or that develops during the hospital stay.
In Critical Access Hospitals (smaller, often rural facilities), the rules are even more explicit. Federal law requires a physician to periodically review and sign the records of all inpatients cared for by nurse practitioners, clinical nurse specialists, or physician assistants. NPs can practice independently in these hospitals for outpatient care when state law allows, but inpatient oversight by a physician is a statutory requirement that CMS cannot waive.
In practice, this means that even in states where NPs have full independent practice authority, the hospital setting often reintroduces physician involvement. Many hospitals also set their own credentialing policies that further define what NPs can and cannot do within their walls, sometimes more restrictively than state law requires.
How State Laws Shape the Differences
The practical answer to “what can a doctor do that an NP cannot” depends heavily on your state. States fall into three categories for NP practice authority:
- Full practice states allow NPs to evaluate, diagnose, order tests, and prescribe medications independently, with no physician involvement required.
- Reduced practice states require NPs to maintain a career-long collaborative agreement with a physician to provide patient care.
- Restricted practice states require direct supervision, delegation, or team management by a physician for NPs to see patients at all.
In a full practice state, your visit with an NP may look virtually identical to a visit with a physician for routine primary care: wellness exams, managing diabetes or blood pressure, treating infections, ordering labs and imaging. In a restricted state, that same NP may need a collaborating physician to co-sign charts, approve treatment plans, or authorize certain prescriptions.
Where NPs Actually Practice
There’s a common assumption that expanding NP independence helps solve the primary care shortage, but the data tells a more complicated story. A study published in February 2026 in the journal Family Practice examined autonomous nurse practitioners in Florida and found that 59% were not practicing primary care at all. The most common settings outside primary care were cosmetic and nonstandard medical or surgical practices, psychiatry and addiction medicine, emergency and urgent care, inpatient medicine, and cardiology.
This doesn’t diminish the value NPs provide, but it’s worth knowing when you’re choosing a provider. If you’re seeking specialized care, the NP treating you may or may not have formal training in that specialty, and there’s no universal requirement that they do before practicing in a new area.
Diagnostic Interpretation
Physicians, particularly radiologists, provide final interpretations on complex diagnostic imaging like MRIs, CT scans, and PET scans. While NPs can order these tests and may review results with you, the official read of a complex imaging study is typically performed by a physician radiologist. State laws vary on whether NPs can independently interpret certain types of imaging, and research shows dramatic state-level variation in how much diagnostic imaging interpretation nonphysician practitioners perform, largely driven by differences in scope-of-practice laws.
For simpler tests like basic X-rays or point-of-care ultrasounds, NPs in many settings can interpret and act on results. But for imaging that requires subspecialty expertise, a physician is almost always the one providing the definitive interpretation that guides your treatment plan.
Legal and Medicolegal Differences
In the legal system, physicians and NPs are sometimes held to different standards. In malpractice cases, expert witnesses generally must demonstrate knowledge of the defendant’s specific specialty and have active clinical practice in that field. Some states, like Virginia, require that expert witnesses have practiced in the defendant’s specialty or a related field within one year of the alleged incident. This can mean that in a malpractice case against a physician, an NP may not qualify as an expert witness, and vice versa, because the training and standards of practice are considered distinct.
This legal distinction reflects a broader reality: while NPs and physicians may treat similar conditions, the legal system often recognizes them as different types of providers with different expectations, training standards, and accountability frameworks.