Try making a doctor’s appointment at your primary care provider’s office or an urgent care clinic, and often, it won’t be with an MD or DO. As more people need more care—and as more types of preventative care are available—offices are increasingly relying on nurse practitioners (NPs) and physician assistants (PAs) to see patients and save costs. 

That’s not necessarily a bad thing; though they don’t have as extensive training as an MD or DO, both nurse practitioners and physician assistants can deal with many of the complaints someone would have at their primary care office.

“An experienced PA or NP can do most of what a primary care physician does,” says Perri Morgan, a professor in family medicine and community health at Duke University School of Medicine who focuses on PAs and NPs in the health care work force. “And many practices find them to be a welcome addition to the bottom line” because they cost less to employ than physicians.  

Nurse practitioners and physician assistants are paid less than doctors are, but in some states they can generate nearly as much income for practices because they can bill at the same rate as doctors, says Dr. David Chan, a professor at the University of California, Berkeley who studies health economics. Doctors make, on average, $239,200 a year, according to the Bureau of Labor Statistics—nearly double what physician assistants and nurse practitioners make. 

In 2023, the most recent year for which data are available, there were 340,319 primary care physicians in the U.S., according to the National Center for Health Workforce Analysis. By contrast, there were an estimated 374,970 nurse practitioners and 29,433 physician assistants working in primary care in 2024. 

Estimates suggest that in a decade, there will be many more NPs and PAs than MDs and DOs across medicine. While the number of physicians in the U.S. is projected to grow by just 3% between 2024 and 2034, according to the Bureau of Labor Statistics, the number of physician assistants is expected to grow by 20%, and the number of nurse anesthetists, nurse midwives, and nurse practitioners is expected to grow by 35% over that time.  

In some states, nurse practitioners and physician assistants must be supervised by a physician to practice. But groups that represent the interests of NPs and PAs are advocating for more independence. They have persuaded many states to pass legislation that allows them to operate without a supervising physician. The American Medical Association, however, has worked to defeat such bills, calling the practice “scope creep” and arguing that it makes patients less safe. 

Here’s what patients should know about PAs, NPs, and what you might get from one type of provider vs. another.

What is a nurse practitioner (NP)?

The technical name for a nurse practitioner is an advanced practice registered nurse, or APRN. There are four main types of APRNs: nurse practitioners, certified registered nurse anesthetists, certified nurse-midwives, and clinical nurse specialists. 

Nurse practitioners can diagnose and treat illnesses, prescribe medications, manage chronic conditions, order and interpret diagnostic tests, and provide preventative care, says Valerie J. Fuller, president of the American Association of Nurse Practitioners (AANP). Fuller says NPs are unique because they are trained in nursing and so are extremely patient-centered. “I think patients who choose a nurse practitioner are really looking for a clinician who can diagnose, treat, manage their health needs, but who also takes the time to listen,” she says.

To become a nurse practitioner, you need an undergraduate nursing degree and a registered nurse license. Then you must go back to school to pursue a graduate degree: either a master of science in nursing or a doctor of nursing practice. After your graduate degree, you must pass a national certifying exam; only then can you receive an APRN license. (Not all states issue a specific APRN license; some issue similar authorization but call it a certification or registry.)

Nurse practitioners have what’s called full practice authority in 27 states, meaning they can practice without being supervised by a physician. That’s up from just 14 states in 2010. And although some states have passed legislation that requires visits with nurse practitioners to be compensated at the same rate as physicians, that’s not the case in all states. Medicare reimburses nurse practitioners at 85% of what they reimburse for physicians, Fuller says. 

Fuller argues that allowing NPs to practice without a physician’s supervision encourages them to open up practices, helping close gaps in care. When Arizona allowed full practice authority, she says, the nurse-practitioner workforce grew by more than 50%. Millions of Americans don’t have access to basic primary care services, she says, and nurse practitioners can step up to help if they’re allowed. 

What is a physician assistant (PA)?

Physician assistants came about in the wake of the Vietnam War, when thousands of medics were returning from overseas and looking for a place to fit in the medical field, says Morgan, of Duke. Today, to recognize their independence, the American Academy of Physician Associates (AAPA) is advocating for PAs to be referred to as “physician associates” rather than “physician assistants.” 

PAs help fill gaps in medical care, just like NPs do. “They are trained as core generalists,” says Chantell Taylor, head of advocacy at AAPA. “They’re attractive to employers looking to lower wait times and increase patient access, particularly in rural and underserved areas.”

To start a PA program, students must have a bachelor’s degree, complete prerequisite coursework, and enter PA school with more than 3,000 hours of patient-contact experience, Taylor says. PA programs usually last three academic years that include more than 2,000 hours of clinical experience. 

That clinical experience includes rotations in family medicine, emergency medicine, surgery, pediatrics, and other specialties, and prepares graduates to evaluate, diagnose, and treat patients across a broad range of medical specialties and practice settings. PAs graduate with a master’s degree—usually a Master of Science in physician assistant studies or a Master of Clinical Health Services—and then must pass the physician assistant certifying exam to receive national certification and obtain a state license.

Some PAs practice in primary care, but others specialize in surgery, oncology, and other areas, assisting doctors and making them more productive, says Morgan. A PA could prep patients for surgery and close a patient up after surgery, for instance, allowing the surgeon to see more patients, she says. “PAs in specialties add at least as much value as ones in primary care,” she says. 

The AAPA is advocating for states to lift the requirement that PAs be supervised by a physician; so far, nine states have done so. Five states have passed legislation to change the title of PA from physician assistant to physician associate. 

Are NPs and PAs as effective as MDs and DOs?

Patients may be hesitant to see a NP or PA because they have less education and medical training than a doctor. There have been recent reports of poorly trained NPs missing key indicators of illness, most notably in a Bloomberg series about the rising numbers of nurse practitioners.

Both AAPA and AANP say that PAs and NPs are essential to provide care in rural and underserved areas with physician shortages, and that having more non-physicians providing care helps increase access for all Americans. The American Medical Association, on the other hand, says that while it supports the role of non-physicians, “they are not a substitute for physicians,” and that numerous studies show that patients want care led by physicians.

The training differences are stark. Physicians complete four years of medical school plus a three-to-seven year residency program, which can include 12,000 to 16,000 hours of clinical training. Nurse practitioners do not have a residency requirement and have about 500-720 hours of clinical training, and PAs are required to have about 2,000 hours of supervised clinical practice. 

“The country is facing a health care workforce shortage, including shortages of both physicians and nurses,” the American Medical Association said in a statement provided to TIME. “One way to alleviate this shortage is by supporting physician-led care teams that leverage the skills of non-physician practitioners while ensuring that all members of the care team work together, under the direction of a physician, toward optimal care for patients.”

What does the research show about the effectiveness of each type of provider? It depends on the study, says Chan of UC Berkeley, who has examined the difference between NPs and physicians in an emergency-room setting. In one study, Chan looked at what happened in emergency rooms when the Veterans Health Administration began allowing nurse practitioners to practice without physician supervision in 2016. His work suggested that NPs ordered more external tests than did physicians, had more patients returning to the ER with infections than did physicians, and were more likely than physicians to prescribe antibiotics. But “the evidence is still kind of limited,” Chan says. Some doctors will have better patient outcomes than some nurse practitioners, but the reverse is true, too.

Other research suggests that both NPs and PAs can be as effective as doctors at taking care of chronic conditions in medically complex patients—and that they can help save money. One study of patients with diabetes seen at the VA found no clinically significant differences in diabetes outcomes of patients seen by a NP, PA, or physician. 

Another study of VA patients with diabetes found that the health care costs were about 7% lower for NP and PA patients than patients who saw a physician, because patients who saw a doctor were more likely to use the emergency room and inpatient services. Morgan of Duke, the lead author of that study, speculates that this is because it might be easier for patients to reach their PA or NP than their physician, allowing  their provider to help them address concerns or adjust medications quickly without having to go to the emergency room. 

What’s most important, experts say, is that NPs and PAs work together with physicians to help fill care gaps and treat patients. Exactly how that team works together is still up for debate. Taylor, of the AAPA, calls the physician-led model “outdated” and argues that it “doesn’t fully leverage all provider types.” The AMA, on the other hand, argues that physician-led, team-based care is higher quality and more cost effective. And both have a number of studies to point to that prove their point. 

“Increasingly, health care is about teams,” Chan says. “So the next question is: How do we best organize teams with NPs and doctors and others?”