Most folks do not. The ideal time is end of first year or second year residency depending upon your availability. It is often better this way. Most Doctors who take Step 3 before residency tend to be AMG's with barley passing step 1 and 2 scores in addition to multiple retakes or IMG's trying to be more competitive for a residency position here in the states. Thats my take on it from what I heard. Hope this helps.