I have already taken Step 2 CK, and wanted to find out if there is any time requirement for how long after you can complete CS. Please provide an official link if you could (I couldn't find anything).
AFAIK, you can take CS anytime before or after CK. Obviously you can't take it on the same day. If your question is whether you need to take the CS within a specified time period after taking CK, I think that depends on individual state medical boards. In general, most states give you 7 years to complete the entire USMLE sequence (1, 2CK, 2CS and 3). http://www.fsmb.org/usmle_eliinitial.html
