What Is a Fellow Doctor? Understanding Medical Fellowships

A fellow doctor is a physician who has completed both medical school and residency, then pursued additional, optional subspecialty training called a fellowship. Premed, resident, fellow, attending, there are a lot of different titles for doctors and soon-to-be doctors, and which one applies depends entirely on where someone is in their training.

So what are the benefits of pursuing a fellowship, and how does a fellow differ from a resident or an attending? In this post, we’ll break down the terminology and the tradeoffs involved.

What Is a Fellow Doctor?

The fellowship itself typically lasts 1-3 years, depending on the subspecialty and program. It’s optional. Fellows are already fully licensed, practicing physicians, so the decision to pursue one comes down to wanting deeper expertise in a narrower slice of medicine rather than needing the credential to work.

For example, a doctor may complete residency and go into practice as a fully credentialed physician in general internal medicine. Or, they may elect to pursue a fellowship to train in a subspecialty of internal medicine, such as cardiology, gastroenterology, nephrology, and many others. During this training, they’re known as a fellow doctor, and once they complete the fellowship, they’re known as a fellowship-trained doctor. 

What Is a Medical Fellowship?

A fellow is the doctor; a fellowship is the training they’re doing. The fellowship is a formal program, typically 1-3 years, in which a fully licensed physician trains in a subspecialty after completing medical school and residency.

Fellowships are accredited by the Accreditation Council for Graduate Medical Education (ACGME) to ensure they meet standards for US graduate medical education. ACGME accredits residency and fellowship programs across dozens of specialties and subspecialties nationwide.

The physician training process begins when medical school graduates enter a residency program in a specific specialty, such as internal medicine, obstetrics and gynecology, surgery, or pediatrics. Completing residency in a specialty allows that physician to enter a fellowship for subspecialization training within that specialty.

For example, doctors who specialize in general surgery during residency may pursue a fellowship in a subspecialty, including hand surgery, pediatric surgery, vascular surgery, colon and rectal surgery, or many others. A fellow subspecializing in hand surgery, for instance, may participate in hundreds of hand surgeries throughout training to earn that subspecialty.

Likewise, doctors who specialize in obstetrics and gynecology (OB/GYN) may subspecialize in reproductive endocrinology, maternal-fetal medicine, gynecologic oncology, or female pelvic medicine and reconstructive surgery through a fellowship.

What Are the Benefits of Pursuing a Medical Fellowship?

A fellowship isn’t required to practice medicine. A doctor can complete residency, get board-certified, and go straight into practice. Fellowship training is necessary only if a doctor wants to specialize further, as many subspecialties are accessible only through it. The choice to pursue one is ultimately personal and comes with trade-offs.

The costs are real. Fellows earn less than physicians who go straight into private practice, and they spend more time training. After 4 years of medical school and 3-7 years of residency, fellows add another 1-3 years before they’re done.

The upside is specialization. Fellowship is the only path into many subspecialties, allowing doctors to develop expertise that would otherwise take years to build through general practice alone. Fellowship-trained doctors are also in high demand, since there’s a general shortage of subspecialists, which often gives them their pick of job opportunities once they finish training. That positioning matters more than ever, given recent changes to how ERAS evaluates research and scholarly work, which are reshaping what it takes to be competitive in residency and fellowship applications.

That shortage cuts both ways. Generalists frequently refer complex cases to fellowship-trained subspecialists, but in many subspecialties, those specialists are so scarce that patients may face long wait times to be seen.

Fellow vs. Resident Doctor: How Do They Differ?

Residency is mandatory; fellowship is not. Beyond that, the two stages differ in a few concrete ways.

1 | Amount of Training

Both residents and fellows have completed 4 years of medical school. Residency lasts anywhere from 3-7 years, depending on the specialty. For example, family medicine runs 3 years, while neurosurgery runs 7. Fellows add another 1-3 years on top of that, with the exact length depending on the subspecialty and program. 

2 | Credentials and Status

A resident hasn’t yet completed the training required to become a board-certified, fully credentialed physician. They’re not yet a full doctor, and they’re supervised by attending physicians throughout residency. They can participate in patient care, but the attending is ultimately responsible for it.

A fellow, by contrast, has already completed residency and is a fully certified physician. They can consult within their subspecialty and can act as attendings themselves, supervising residents.

3 | Pay

The average medical resident earns about $75,000 a year. Fellows earn a similar, possibly somewhat higher, salary, though both fall well below what a fully practicing specialist makes.

That gap closes fast once the fellowship ends. Fellowship-trained doctors can be highly sought-after, and it’s possible for them to earn hundreds of thousands of dollars more than a physician who completed residency alone.

A fellow’s salary depends on their specialty or subspecialty, city, country, and institution. Once the fellowship ends, the pay difference between specialties becomes stark. See our breakdowns of the highest-paid and lowest-paid medical specialties for the full picture.

The Complete Doctor Journey

Becoming a doctor, especially a fellowship-trained doctor practicing in a subspecialty, is quite the endeavor. Here’s the full path, and the different titles that come with each stage.

1 | Premed

All future doctors start with a bachelor’s degree. Premed is not a major; it’s a term for students planning to apply to medical school after college. Getting there requires several prerequisites, including biology, physics, general and organic chemistry, biochemistry, English, and math.

2 | Medical Student

Medical school generally lasts 4 years and leads to a degree as a Doctor of Medicine or a Doctor of Osteopathic Medicine. Typically, the first 2 years are mostly classroom-based, while the final 2 shift toward hands-on training in the hospital and clinic.

3 | Resident

Residency adds another 3-7 years of training in a chosen specialty, supervised by an attending physician who remains ultimately responsible for patient care. Residents perform exams and procedures under that supervision, building toward the certification that lets them practice independently.

4 | (Optional) Fellows

So what does it mean if a doctor is a fellow? Once residency is complete, a physician is already certified and free to practice. A fellow is one who chooses, instead, to pursue further training in a subspecialty. Fellowship isn’t required to practice medicine generally, but it’s the only path into many subspecialties, which is why fellowship-trained doctors are the ones you’ll find treating the most specific, complex cases within a field.

5 | Attendings

Attending physicians are fully credentialed doctors, fellowship-trained or not. The term distinguishes supervising physicians from those still in training who aren’t practicing independently yet.

Finding the Right Specialty or Subspecialty for You

If you’re a medical student trying to choose a specialty or subspecialty, our So You Want to Be… series breaks down what it’s actually like to practice in dozens of different fields, with new additions added regularly.

Still narrowing things down? This Specialty Quiz can help point you toward the fields worth exploring further before you commit to a residency, let alone a fellowship.

Fellow Doctors and Fellowships FAQ

What is the difference between a resident and a fellow?

A resident is training in a primary specialty and hasn’t yet completed the requirements to practice independently. A fellow has already finished residency, is a fully credentialed physician, and is pursuing optional, additional training in a subspecialty.

How long does a medical fellowship take?

Most fellowships last 1-3 years, depending on the subspecialty and program. This comes after 4 years of medical school and 3-7 years of residency, so a fellowship-trained doctor may not finish training until 8-14 years after starting medical school.

Is a fellowship required to become a doctor?

No. A physician can complete residency, become board-certified, and practice independently without ever pursuing a fellowship. Fellowship is only necessary for doctors who want to subspecialize, since many subspecialties are accessible only through fellowship training.

Do fellows get paid?

Yes. Fellows are fully licensed physicians and receive a salary during their fellowship, typically similar to or somewhat higher than a resident’s pay, though still well below what a fully practicing specialist earns.

What is the difference between a fellow and an attending?

Both are fully credentialed physicians who can practice independently. The key difference is training status: a fellow is still in subspecialty training, working under the broader structure of a fellowship program, while an attending has completed all formal training and practices, and supervises without that structure.