The types of doctors in the United States are defined by residency training, and the 24 ABMS member boards certify 38 specialties and 90 subspecialties. Family medicine, internal medicine and pediatrics take 3 years of residency after medical school, while neurological surgery takes 7. Each type cares for a different patient group, organ system or setting.
Every type of doctor starts from the same base: a bachelor’s degree, 4 years of MD or DO school and national licensing exams, then a residency in one specialty and, for subspecialists, a fellowship on top. The full timeline from college to independent practice adds those stages together. Below you will find each type of doctor, how long its training runs and what the work involves day to day.
How Every Type of Doctor Trains
Physicians and surgeons need a bachelor’s degree and a 4-year medical degree, and depending on their specialty, they also need 3 to 9 years in internship and residency programs, according to the Bureau of Labor Statistics occupational profile for physicians and surgeons. Subspecialties add a fellowship of 1 to 3 years.
Licensing exams run alongside training. MD students take the three-Step United States Medical Licensing Examination, whose results state boards use when granting the initial license to practice medicine. DO students take COMLEX-USA, a three-level exam that is also a graduation requirement for the DO degree and is used for entry into residency.
Residency is the point where a medical graduate becomes a specific type of doctor. The Accreditation Council for Graduate Medical Education lists 28 residency areas, from allergy and immunology to urology, one of which is the one-year transitional year rather than a specialty. Each specialty’s 2026 program requirements fix the length: an internal medicine residency must provide 36 months of supervised education, while other specialties run 4 to 7 years.
After residency, doctors sit for board certification. The American Board of Medical Specialties lists 38 specialties and 90 subspecialties certified by its 24 member boards. A subspecialty, such as cardiology under internal medicine or pediatric surgery under surgery, requires a fellowship after the parent residency.
Do MD and DO Doctors Become the Same Types of Doctors?
Yes. ACGME eligibility rules for 2026 accept graduates of LCME-accredited MD schools and COCA-accredited colleges of osteopathic medicine for the same residencies, so a DO graduate can train as any type of doctor listed below. ACGME also accredits osteopathic neuromusculoskeletal medicine, a 36-month residency.
Types of Doctors at a Glance
The table lists every core specialty with its residency length from the 2026 ACGME program requirements. “Years” means years after medical school, before any fellowship.
| Type of doctor | Residency length (ACGME 2026) | What they do | IMA guide |
|---|---|---|---|
| Family medicine | 3 years | Ongoing general care for patients of every age, often several members of one household | |
| Internal medicine | 3 years | Nonsurgical diagnosis and care of adults, covering internal organs and body systems | |
| Pediatrics | 3 years | Care of infants, children, adolescents and young adults, including vaccinations and common illnesses | How to become a pediatrician |
| Emergency medicine | 3 or 4 years (36- and 48-month formats) | Evaluates and stabilizes patients with sudden illness or injury | How to become an emergency room doctor |
| Anesthesiology | 4 years (36 months of clinical anesthesia plus 12 months of clinical skills) | Anesthesia and pain relief for surgery, labor and chronic pain | How to become an anesthesiologist |
| Dermatology | 4 years (a clinical year, then 36 months) | Conditions of the skin, hair and nails, including skin cancers | How to become a dermatologist |
| Neurology | 4 years (48 months) | Disorders of the brain and nervous system, such as epilepsy and ALS | How to become a neurologist |
| Psychiatry | 4 years | Diagnoses and treats mental illness with therapy, hospital care and medication | How to become a psychiatrist |
| Obstetrics and gynecology | 4 years | Reproductive health, pregnancy and childbirth | How to become an OB/GYN |
| Ophthalmology | 4 years (48 months, or a preliminary year plus 36 months) | Eye conditions, including surgery for vision problems and glaucoma | |
| Pathology | 4 years for anatomic and clinical pathology, 3 for anatomic only | Diagnoses disease from body tissues, fluids and organs | |
| Physical medicine and rehabilitation | 4 years (48 months, or 36 after a clinical year) | Restores function after injury, stroke and long-term illness | |
| Diagnostic radiology | 5 years (48 months of radiology plus a clinical year) | Interprets X-rays, CT, MRI and ultrasound, and performs minimally invasive treatments | How to become a radiologist |
| Radiation oncology | 5 years (48 months after a clinical year) | Treats cancer with radiation | |
| Nuclear medicine | 3 years | Diagnosis and therapy using radioactive tracers | |
| Preventive medicine | 2 years, or 3 with a clinical year | Public health, disease prevention, occupational and aerospace medicine | |
| Medical genetics and genomics | 2 years | Diagnosis and care of inherited and genetic conditions | |
| Allergy and immunology | 2 years, after internal medicine or pediatrics residency | Asthma, allergies and disorders of the immune system | |
| Osteopathic neuromusculoskeletal medicine | 3 years | Musculoskeletal and structural care using osteopathic methods | |
| General surgery | 5 years | Operations on the abdomen, digestive tract, breast, skin and soft tissue | Types of surgeons and surgical specialties |
| Orthopaedic surgery | 5 years | Injuries and conditions of bones, muscles, ligaments and tendons | |
| Otolaryngology (ENT) | 5 years | Surgery and medical care of the ear, nose, throat, head and neck | |
| Urology | 5 years | Urinary tract and male reproductive organs | |
| Interventional radiology (integrated) | 5 or 6 years | Image-guided procedures through small incisions and catheters | |
| Plastic surgery (integrated) | 6 years | Reconstructive surgery after injury, cancer or birth differences, plus cosmetic surgery | |
| Thoracic surgery (integrated) | 6 years | Surgery of the heart, lungs, esophagus and chest | |
| Neurological surgery | 7 years | Surgery of the brain, spine and peripheral nerves |
Which Doctors Train the Longest?
Neurological surgery has the longest core residency: the 2026 neurological surgery requirements set the program at 84 months, or 7 years. Integrated plastic surgery and integrated thoracic surgery each run 72 months, and the integrated interventional radiology track comes in a 60-month or 72-month format. Add 4 years of college and 4 years of medical school, and a neurosurgeon who goes straight through finishes training 15 years after high school. Fellowships can push some paths further: ACGME sets congenital cardiac surgery at 24 more months, taken only after earlier surgical fellowship training.
Which Types of Doctors Have the Shortest Residency?
Family medicine, internal medicine, pediatrics, nuclear medicine and osteopathic neuromusculoskeletal medicine each run 36 months, and emergency medicine offers a 36-month format. Preventive medicine is configured in 24-month and 36-month formats, with both including 24 months of preventive medicine education. A family physician who goes straight through practices independently 11 years after high school.
Subspecialists: Types of Doctors Who Complete a Fellowship
Many of the doctors patients see by name, such as cardiologists or gastroenterologists, are subspecialists. They finish a full residency first, usually internal medicine, pediatrics or surgery, then a fellowship in one organ system, disease group or procedure. The lengths below come from the 2026 ACGME program requirements for each fellowship.
| Subspecialist | Parent residency | Fellowship length |
|---|---|---|
| Cardiologist (cardiovascular disease) | Internal medicine | 3 years |
| Gastroenterologist | Internal medicine | 3 years |
| Hematologist and medical oncologist | Internal medicine | 3 years |
| Pulmonary and critical care physician | Internal medicine | 3 years |
| Nephrologist | Internal medicine | 2 years |
| Rheumatologist | Internal medicine | 2 years |
| Endocrinologist | Internal medicine | 2 years |
| Infectious disease physician | Internal medicine | 2 years |
| Pediatric surgeon | General surgery | 2 years |
| Neurotologist | Otolaryngology | 2 years |
| Sports medicine physician | Family medicine, emergency medicine and other primary specialties | 1 year |
| Colon and rectal surgeon | General surgery | 1 year |
| Hand surgeon | Orthopaedic, plastic or general surgery | 1 year |
| Dermatopathologist | Dermatology or pathology | 1 year |
| Addiction psychiatrist | Psychiatry | 1 year |
| Epileptologist | Neurology | 1 year |
| Surgical critical care physician | General surgery | 1 year |
What Is the Difference Between a Specialist and a Subspecialist?
A specialist has completed a residency, such as internal medicine, and can be board certified in that specialty. A subspecialist has gone on to a fellowship and a second certification in a narrower field. Take cardiology as a worked example: 4 years of college, 4 years of medical school, 3 years of internal medicine residency and a 36-month cardiovascular disease fellowship add up to 14 years after high school. The cardiologist training and certification guide covers the steps in order.
Types of Doctors Grouped by How They Work
Residency length tells you how long the road is. How a type of doctor spends the day tells you whether you will enjoy it. Most specialties fall into a handful of working styles.
- Primary care: family medicine, general internal medicine and pediatrics. Long-term relationships, prevention and the first visit for most new problems.
- Acute and hospital care: emergency medicine, anesthesiology, critical care and hospital medicine. Shift-based work, fast decisions and patients you may see only once.
- Diagnostic medicine: radiology, pathology and nuclear medicine. Most work happens through images, tissue and lab results, with less face-to-face time.
- Surgery: general surgery and its relatives, from orthopaedics to neurosurgery. Long residencies and operating room time; the surgical specialties guide linked in the table lists every one.
- Brain and behavior: neurology and psychiatry. Detailed histories, long-term conditions and a mix of clinic and hospital care.
- Reproductive and women’s health: obstetrics and gynecology, which combines clinic visits, deliveries and surgery.
Which Types of Doctors See Patients of All Ages?
Family medicine physicians care for patients of every age, which is why a single family doctor can see a parent and a child in the same afternoon. Emergency physicians also treat every age group. Most other specialties split by age: pediatricians care for infants through young adults, internists care for adults, and fields such as pediatric surgery and pediatric dermatology exist as separate fellowships for children.
How Much Different Types of Doctors Earn
BLS reports a median annual wage of $275,930 for physicians and surgeons in May 2025. The lowest 10 percent earned less than $76,560 and the highest 10 percent earned more than $488,320. The table shows the median wage by BLS occupation.
| BLS occupation | Median annual wage, May 2025 |
|---|---|
| Pediatric surgeons | $559,030 median |
| Cardiologists | $496,010 median |
| Radiologists | $420,860 median |
| Surgeons, all other | $414,010 median |
| Anesthesiologists | $391,490 median |
| Orthopedic surgeons, except pediatric | $358,550 median |
| Emergency medicine physicians | $335,550 median |
| Dermatologists | $328,730 median |
| Pathologists | $312,400 median |
| Ophthalmologists, except pediatric | $300,080 median |
| Obstetricians and gynecologists | $292,910 median |
| Psychiatrists | $281,870 median |
| General internal medicine physicians | $256,560 median |
| Neurologists | $248,560 median |
| Family medicine physicians | $244,180 median |
| Pediatricians, general | $210,040 median |
The broad pattern: procedure-heavy and surgical types of doctors sit at the top, and primary care types sit at the bottom, with general pediatricians earning the lowest median wage on the list. Longer training and procedural work tend to go with higher pay, though family medicine and pediatrics keep doctors in practice years earlier. BLS counted about 862,800 physician and surgeon jobs in 2025 and projects employment to grow 4 percent from 2025 to 2035.
How to Choose Among the Types of Doctors
You do not pick a specialty before medical school; you apply for residency during the final year. Still, knowing the types of doctors early helps you choose clinical experience with purpose. Ask yourself these questions as you go:
- Which patients do you want: children, adults, older adults or everyone?
- Do you want long relationships with patients or single encounters in a crisis?
- Are you drawn to procedures and the operating room, or to diagnosis and conversation?
- How many years of residency and fellowship are you willing to train after medical school: 3, 5 or 7 or more?
- Do you prefer a predictable clinic week or shift work that includes nights and weekends?
The best way to answer those questions is time in real clinical settings. Shadowing, hospital volunteering and clinical jobs in college let you see several types of doctors at work before you commit to one path.
IMA’s pre-med internships abroad place students in hospitals and clinics where, under the supervision of licensed clinicians, they take vital signs, help with patient intake and triage, conduct basic patient interviews and join ward rounds across several departments. Rotating through different services shows you how a surgeon’s day differs from a pediatrician’s. How those hours are classified on your application is each school’s decision.
Frequently Asked Questions
How many types of doctors are there?
The 24 member boards of the American Board of Medical Specialties certify 38 specialties and 90 subspecialties. ACGME accredits residencies in 28 areas, one of which is the transitional year, so the count you see depends on whether subspecialties such as cardiology or gastroenterology are included.
Which type of doctor has the shortest training?
Family medicine, internal medicine and pediatrics have the shortest standard residencies at 36 months under the 2026 ACGME requirements, and emergency medicine also offers a 36-month format. Added to college and medical school, that is 11 years after high school.
Which type of doctor trains the longest?
Neurological surgery has the longest core residency at 84 months. Integrated plastic surgery and integrated thoracic surgery run 72 months, and fellowships such as congenital cardiac surgery add 24 more months after earlier surgical fellowship training.
Which types of doctors earn the most?
In BLS data for May 2025, pediatric surgeons had the highest median wage at $559,030, followed by cardiologists at $496,010 and radiologists at $420,860. The median wage for all physicians and surgeons was $275,930.
What is the difference between a residency and a fellowship?
A residency trains a medical school graduate in a specialty such as internal medicine or surgery and lasts 3 to 7 years. A fellowship comes after residency and trains a doctor in a subspecialty, such as cardiology or pediatric surgery, usually for 1 to 3 years.
Is family medicine the same as internal medicine?
No. Both are 36-month primary care residencies, but family medicine physicians care for patients of every age, while internal medicine physicians care for adults. Internal medicine is also the parent residency for most medical subspecialties, including cardiology, gastroenterology and nephrology.
Can a DO become any type of doctor?
Yes. ACGME residency eligibility rules accept graduates of COCA-accredited colleges of osteopathic medicine on the same terms as graduates of LCME-accredited MD schools, so DO graduates can enter any specialty. DO students take COMLEX-USA, the osteopathic licensing exam.
