We're on a block system, so we generally have one big exam every 4-6 weeks at the end of the block. The exams are all for credit, although second year you do some practice step exams. Otherwise, every week there's a formative quiz that gives you some practice questions to do on your own time. We're the standard sort of pass/fail. M2s are currently in the middle of their hardcore Step prep and take Step 1 before beginning 3rd year. They get a chunk of time for dedicated study, but I don't know the details, and I haven't heard much of anything about Step 2. I'm pretty sure there are some clerkships that are elsewhere, but almost everything is at the main hospital here.