<p>Depends on your specialty. Residencies can last anywhere from three to seven years. Fellowships are usually either one or two. The residency is required to practice medicine. A fellowship entails further specialization.</p>
<p>In my hospital fellowships in our program are 3 years. One must complete internship and residency prior to the fellowship years.
The first year of fellowship is a clincal year---intense inpatient and outpatient work, learning how to be a sub-specialist. The last 2 years involve intense outpatient clinic work, occasional inpatient coverage but primarily these years are reserved for research...depending on the interest of the fellow it may be clinical research or basic/bench research</p>