What is the Difference between a PA and MD?

This is a question I often get from prospective students who are looking into the PA program, except its framed, “Why did you choose to become a Physician Assistant and not an MD?”. It’s a good question, but I thought it would be more constructive to discuss the differences between the two professions as well as their similarities. Answers are based on PAs and MDs practicing in Ontario, Canada.

MD vs. PA – Education Pathway

Physicians have a much longer duration of education:

  • Medical School: 3 to 4 years. The first half usually consists of didactic learning and medical foundations (1st and 2nd year students), the second half involves “clerkship” where medical students complete clinical rotations. 
  • CaRMS: Application process to rank residencies.
  • Residency: Depending on the specialty (family 2 years, other specialties 4 to 5 years).
  • Fellowship: Extra training to sub-specialize within the specialty (1 to 2 years). This is considered a “short-term” training program.
  • Apply for a Physician position: Finding work as an MD as a generalist is not difficult since there is a shortage of family physicians. To be affiliated with a teaching hospital, positions are certainly more competitive. It is easier to find work in remote settings and community hospitals.
  • Total duration before becoming “staff” – 6 (primary care) to 12 years (specialist) (not including undergraduate education before medical school)

Physician Assistant education is shorter in duration:

  • Physician Assistant School: 2 years. The first half (year one) includes establishing medical foundations, the second half involves clerkship where PA students complete clinical rotations in different areas of medicine.
  • Apply for a PA position: PA’s graduate as generalists and may work immediately after graduation in any area of medicine.
  • The total duration of training before becoming “staff”: 2 years (not including undergraduate education before PA school)
PA or MD? Meet Sundance who has done both.

“Sundance describes her choice to become a physician assistant student (PA vs MD). A prior medical student, she explains her decision to become a PA.”

MD vs. PA – Teaching Philosophy & Professional Competencies

Both physicians and physician assistants use the CanMEDS Framework to determine the knowledge, skills and abilities required to treat patients. For Physician Assistants in Canada, this is outlined in the Can-MedsPA. In summary, its actually not that different.

For instance, McMaster University’s PA Education Program has a large part of their curriculum based off of the medical school curriculum. Teaching philosophy, approach and use of the medical model is almost identical to that of physicians in training. PAs learn to question, think and diagnose like doctors as Physician Assistants are educated in the medical model.

MD vs. PA – Scope of Practice

Physicians are the “most responsible provider” and have full liability over the care of their patients. They see their own list of patients, can work in an outpatient clinic, in the hospital or do a combination of both. As staff at hospital they also perform surgeries, or obtain hospital privileges to do so. The Principles and Duties of Practice are outlined on CPSO.

Physician Assistants are not independent practitioners, therefore clinical skills and procedures performed depend on several factors:

  • What the PA can perform is dependent on the skill/procedure/scope of practice of the supervising physician. If the supervising MD doesn’t perform the task to be delegated, then the PA should not perform the task either. For example, if the physician does not normally prescribe a certain medication, the PA should not prescribe that medication either without first consulting the physician.
  • What is performed by the PA must be delegated by the supervising physician. Frequently delegated tasks can be outlined in a carefully crafted medical directive.
  • PAs can perform 80-90% of what a physician may do, focusing more often on less acute, pressing problems to offload work from the supervising physician. This allows the physician to focus on more complex problems, patients that require more time, or other academic/research endeavours.

Research, Business Startups, Journalism, Advocacy, Volunteerism, and Consulting are all aspects of medicine and business that both physicians and physician assistants can partake in. 

Fore more information on Scope of Practice, see Health Force Ontario’s “Defining the Physician Assistant Role in Ontario” document.

MD vs PA – Lateral Mobility

If a Physician were to be interested in switching specialties completely, it is much more difficult and would require additional certification or years of training. Generally if one day a Urologist wishes to become an Orthopaedic Surgeon, this would involve taking on additional years of training.

Physician Assistants may switch between specialties without requirement for additional training or certification. In fact, it is not uncommon for physician assistants to start in one area of medicine, and end up in another over the course of several years. My mentor started out in Cardiothoracic Surgery, switched to Plastic Surgery and eventually ended up in Emergency Medicine working full time as a PA. Another American PA I know of works part time in a Family Medicine practice, and other days of the week will work in a Dermatology practice. Prior to this she had been working in an Orthopaedic Surgery Practice.

MD vs PA – Work-Life Balance

Both a physician and physician assistant can cater their work schedule to best suit their lifestyle practices. For instance, if either profession wishes to only work 3 days per week for whatever reason, a physician simply sets their schedule, whereas a PA will apply for part time positions. PA contracts may or may not require shift work or call duty, however physicians who take up posts at hospitals are usually required to do call or shift work (e.g. in the ER, or in surgical/hospitalist specialties).

For instance, I work in Orthopaedic Surgery as a PA, however unlike my supervising physicians, I do not take on call, and work 8 am to 4 pm Monday to Friday with no weekends.

MD vs PA – Liability

Physicians have ultimate liability as the “most responsible physician” that come along with having more independence, autonomy and responsibility. They have their own liability insurance which they pay into annually.

Physician Assistants: Negligence on part of the PA may expose the supervising MD to liability as well (similar to the liability that occurs with supervising medical students/learners/residents). Physician Assistants who work in hospitals may be covered through HIROC, otherwise PAs may obtain their own liability insurance

For more information on Liability of Employment of PA’s, read the Ontario Hospital Association Liability of PA’s document.

MD vs PA – Compensation

Time: Physicians lead very busy lifestyles, their schedule includes performing call, surgeries, outpatient clinics, consultations to other services, and in patient wards. They manage and oversee staff and their personal clinics – which involves a lot of work similar to managing a small business. PAs are essentially “employed/supervised under physicians” and thus may, in comparison, provide more time for leisure, and having more time for family

Salary: Physicians are extremely comfortable (typical salary for family physicians in Ontario is between $200,000 to $300,000 depending on the scope of practice, with specialists making more). However, as medical residents, they start off making approximately ~$51,000 per year in Ontario. Keep in mind that physicians also have to pay overhead if they run their own clinics – this includes rent for their office, salaries of staff including administrative assistants / medical secretaries, PAs/NPs or RNs they may have hired, medical supplies, and EMR software, etc.

On the other hand, Physician Assistant Salary is comfortable and enough for a good standard of living. Starting salary for physician assistants starts at $84,000 per year including benefits in Ontario. Competitive salaries are higher and there are a few Physician Assistants on the Ontario Sunshine List who make $100,000+, with pay scale and benefits. PAs do not pay for overhead since they do not run their own clinics.

MD vs PA – Regulation

In Ontario – Physician Assistants are currently not a regulated profession due to not meeting the requirements for threshold of harm. At this time in Ontario, lack of regulation does not prevent PAs from practicing or affect the quality of care currently delivered; it seems to serve more as a barrier to moving the profession forward in terms of Advocacy and a larger stakeholder acceptance. Paramedics are another category of health care professional that are not regulated as well.

In Ontario, MDs are a “self-regulated” profession. The College of Physicians and Surgeons of Ontario (CPSO) is the  body that regulates the practice of medicine amongst physicians.

PA role is NOT a stepping stone to becoming a doctor, neither do PAs replace MDs. These are two distinct careers in which both professions practice medicine. Don’t forget to read how the PA/MD relationship works!

Final. Notes


  1. Alicia P September 20, 2017 at 4:16 pm - Reply

    Excellent read! I think it’s also worth noting that although Physicians make a higher salary, they also accumulate much more debt during their studies than PAs do.

    • Anne Dang September 29, 2017 at 8:38 am

      Absolutely agree. In addition most physicians are not salaried and function as “professional corporations”. They also accumulate expenses for running their businesses (e.g. paying for EMR, office space, telephone, internet, staff, clinical supplies, etc)

  2. Adrian January 21, 2023 at 11:08 pm - Reply

    It is extremely misleading to claim that “PAs can perform 80-90% of what a physician may do…”. As a fully trained ER doc, this is patently false. A GP alone has 3x the training/education of a PA, and each year of MD training is not equivalent to those in a PA program.

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