The medical education includes training from entry level to being a specialist. This system includes medical school, internship, residency, fellowship and certification from the board. Admission to medical school requires you to go through 2-3 years of Pre med training. After completion of the internship, doctors look to take up residencies. This program can take from as few as three years to seven years. If you wish to take to highly specialized fields like cardiology, oncology, etc, you will have to dedicate a lot more years on it. Fellowship involves research and can take 1-3 years.