To become a cardiologist in the US, you earn a bachelor's degree, complete four years of medical school, then a 36-month internal medicine residency. After that comes a cardiovascular disease fellowship of at least 36 months, including 24 clinical months. Board certification means passing the American Board of Internal Medicine's internal medicine exam first, then its cardiovascular disease exam.
Cardiology is one of the longest and best-paid routes in medicine, and it's built on top of internal medicine, so you can't skip straight to the heart. I've built this guide from the Bureau of Labor Statistics (BLS) physicians and surgeons profile and the American Board of Internal Medicine (ABIM) certification policies, all read on 26 October 2026.
The cardiology route at a glance
| Stage | What it involves | Length |
|---|---|---|
| Bachelor's degree | Any major, usually with biology or physical science | Usually 4 years |
| Medical school | M.D. or D.O., with entry based partly on the MCAT | 4 years |
| Internal medicine residency | Accredited training, reported in 12-month blocks | 36 months |
| ABIM internal medicine certification | Pass the internal medicine certification exam | After residency |
| Cardiovascular disease fellowship | Accredited fellowship with required procedures | At least 36 months, 24 clinical |
| ABIM cardiology certification | Pass the Cardiovascular Disease Certification Examination | After fellowship |
Step by step
- Get into medical school. BLS says no specific undergraduate major is required, but applicants usually study biology, physical science or a health field. Schools look at transcripts, MCAT scores, recommendation letters and interviews.
- Finish medical school. The first phase is classroom and lab work. The second is supervised clinical rotations, including internal medicine.
- Complete an internal medicine residency. ABIM requires 36 months of accredited residency, with at least 30 months in general internal medicine, subspecialty internal medicine and emergency medicine.
- Get licensed and certified in internal medicine. All states require physicians to be licensed, which includes passing standardised national exams. You must already hold ABIM internal medicine certification when you apply for the cardiology exam.
- Complete a cardiology fellowship. ABIM sets a minimum of 36 months, with 24 months of clinical training.
- Pass the cardiology board exam. The Cardiovascular Disease Certification Examination completes the route.
The fellowship rules that trip people up
ABIM's cardiology policy has a few conditions worth knowing before you plan your training:
- The fellowship must be accredited by the ACGME, the Royal College of Physicians and Surgeons of Canada, or the Collège des médecins du Québec.
- No credit is given for subspecialty training completed outside an accredited US or Canadian program.
- Training done before finishing your M.D. or D.O., or time as a chief medical resident, doesn't count towards the fellowship.
- Rotations can't be counted twice towards both internal medicine and cardiology requirements.
- Your required training, including vacation time, must be complete by 31 October of the year you sit the exam.
The fellowship also lists required procedures, including advanced cardiac life support with cardioversion, and electrocardiography.
What cardiologists earn
| Occupation (BLS, May 2025) | Median annual pay | Jobs in 2025 |
|---|---|---|
| Pediatric surgeons | $559,030 | 1,300 |
| Cardiologists | $496,010 | 18,500 |
| Radiologists | $420,860 | 28,700 |
| Neurologists | $248,560 | 11,400 |
| All physicians and surgeons | $275,930 | 862,800 |
Those figures are as of October 2026. Here's the insight most guides skip: in the BLS table, cardiologists have the highest median pay of any non-surgical specialty, second only to pediatric surgeons. Yet there are only 18,500 cardiologist jobs. Neurologists, who also treat a vital organ system, earn about half as much. BLS projects cardiologist jobs to rise from 18,500 to 19,400 between 2025 and 2035.
Do you have to be board certified?
Not legally. BLS says board certification in a specialty isn't required for physicians, but it may increase your job opportunities, and in practice most cardiology roles will expect it. What's always required is a state medical licence: you must graduate from an accredited medical school, complete residency and pass standardised national exams. Each state's medical board sets the details, so check yours before you plan where to train.
There are ways to shorten the front end. BLS notes that some medical schools offer combined undergraduate and medical programs lasting 6 to 8 years. Others offer combined degrees such as M.D.-Ph.D., which can suit you if you're drawn to cardiology research rather than purely clinical work. ABIM also runs a Research Pathway that combines core clinical training with structured research for physicians who want a research career.
What cardiologists do
BLS describes cardiologists as physicians who diagnose and treat diseases or conditions of the heart and blood vessels, such as valve problems, high blood pressure and heart attacks. They may work with adults or specialise in pediatrics, usually newborns through age 21. Pediatric cardiologists focus more on conditions children are born with than on those that develop later in life.
Many physicians work long shifts, which may include irregular and overnight hours or being on call. That's worth weighing honestly, because you'll be in your thirties before you finish training and the on-call pattern doesn't disappear once you're qualified. If you like imaging and diagnosis more than direct patient care, compare this route with becoming a radiologist. If acute care in the operating room appeals, read how to become an anesthesiologist.
My verdict
Cardiology pays at the very top of medicine, but you'll train for at least 14 years after high school before you're board certified: four years of college, four of medical school, three of internal medicine and three of cardiology. Strong science grades, a competitive MCAT score and early exposure to internal medicine all help. Go in expecting competition for fellowship places, since there are only 18,500 cardiologist jobs in the whole country.
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Another specialty with a very long residency is set out in the neurosurgeon route.
Frequently asked questions
How long does it take to become a cardiologist?
Usually about 14 years after high school: four years of college, four of medical school, a 36-month internal medicine residency and a cardiology fellowship of at least 36 months.
Do you need to be an internist before becoming a cardiologist?
Yes, for ABIM certification. You must already be certified in internal medicine by ABIM when you apply for the cardiovascular disease exam.
How much do cardiologists make?
BLS reports a median annual wage of $496,010 for cardiologists in May 2025.
How many cardiologists are there in the US?
BLS counts 18,500 cardiologist jobs in 2025 and projects 19,400 by 2035.
Does cardiology training abroad count?
Not for ABIM subspecialty certification. ABIM gives no credit for training outside an accredited US or Canadian program.
What does a cardiologist treat?
BLS says cardiologists diagnose and treat diseases and conditions of the heart and blood vessels, such as valve problems, high blood pressure and heart attacks.
