If youre a med student who has recently finished their clerkship this is a pretty simple exam but the thing is that because there are less questions than step 2 ck everything question counts...for study materials i used first aid for step 2 ck, step 2 secrets, USMLEWORLD STEP 2 (MOST IMPORTANT), and i read through the ethics and public health section of toronto notes (even if you dont read through this section youll probably get most of the questions right they arent that specific)...some ppl study for 2 months, some ppl study for 2 weeks, it depends on yourself and how comfortable you are with the material..hope that helps
