I'm a pgy 1 IM switching into OB/GYN. One thing you should know is that there are gme funding issues when it comes to switching from 3 yr program to a 4 yr program. The 4yr program that you're switching into will not get fully funded for your last year. Nevertheless, this is not an issue for most programs. Just be aware of it. Acog allows you to receive 6 mo credit however this is program director dependent. Mine did not allow it. Although having a year is very beneficial in practice, and most attending will smile on your experience during your interviews, most ob programs have dropped their primary care rotations. Some still require a month or so of Wards, MICU and er but a lot were dropping them and getting their primary care requirements through ambulatory clinics. THE MAIN THING YOU SHOULD KNOW IS ---- that you do not have to go through the match again!! The match is only for first time graduating US seniors. You can ask the program for a prematch offer - meaning that they would take a spot out of the match for you. IMGs do it all the time. This is possible however most OB/GYN programs claim to only offer all positions through the match. During your interviews press your primary care experience as an IM grad and how you would utilize this experience during ob residency, etc. Another thing - make sure you dont use up all of your vacation time- keep 2 weeks for the end of the year. I'm currently doing orientation in one state and having to travel back to my institution to work in order to get credit for the year. Bummer!! Good luck