Well, it can be sticky. Being fluent in ASL won't mean that you can interpret. It helps, but it is not what it's all about. If you were a CODA, you would probably do well on the RID test (If you grew up interpreting for your folks a lot).
At the college I took my IPP, it was technically required to take at least 1 year of ASL at that school. I took 2 years at a different school. I ended up meeting with the head of the program (who is Deaf) and she tested me on my signing skills and gave me the okay to start the program without taking a class there.
I imagine it will be the same for many programs. If you retained your signing skills over the years, schedule an interview for an IPP/ITP and get in that way. Of course, if you feel your skills need brushing up, hang back and take at least a semester of courses and be sure to mingle with the Deaf Community in your area.