The time table for taking step 3 varies based on how well you want to perform on step 3, which depends on your career goals and prior step experiences. If you want to pursue fellowship and your prelim year is in internal medicine, then taking it later in PGY1 may be more beneficial. Internal medicine prelims usually receive a lot of first-hand experience on topics that are highly pertinent to the step 3 exam, and in such cases, taking the exam later can improve your score. Also, if you've done well on your previous step exams, you should have little to no problem doing well on step 3 no matter when you take it. If your goal is simply to pass step 3, then taking it in august or september shouldn't be a problem. Good luck, and I hope this helps! M.D. author/editor with BoardVitals