A common question that comes up frequently is: "I don't want to complete my residency training. Should I just get my medical license and start working?"
As you can imagine, many residents don't enjoy residency training. The grueling hours and the sleep deprivation can be disheartening.
Back in the "old days," it was relatively easy to finish internship and practice medicine as a GP (general practitioner). Many states will still grant a medical license to a medical school graduate who has completed a single year of post-graduate training (internship) if you graduated from a U.S. medical school. If you're an international/foreign medical graduate (IMG or FMG), then you'll be required to complete 2-3 years of residency training in many states.
Right now, Nevada appears to be the only state that requires 3 years of residency for U.S. medical graduates who wish to obtain a medical license.
The Federation of State Medical Boards (FSMB) maintains a chart that outlines the State-specific Requirements for Initial Medical Licensure. The current version was updated in June 2009 and you can view it here.