for IMG's to be eligible for the match, they have to pass Step 1, Step 2, and the CSA by January 31 of the Match year. However... if you don't take the CSA by January 31, but you are registered for it, and schedule a date before June, and you have completed both steps, you are still eligible for post match.

What I mean to say is this (more clearly)... even if you don't complete the CSA by the Jan. 31 deadline for the match, you can still participate in the post match scramble through NRMP.