Yes, AIP occurs pretty much at the end of the process, or at least that has been the case so far. Most apps get SA, then AIP then DM, all in a matter of a few days or weeks, near the end of the process, around the 10-12 month mark, well after the medical.
Medicals used to be requested around 140-160 days after app was received but then they stopped doing that, now med request comes pretty much when they feel like it, lol. For some May applicants, they still haven't received med request. For others, it has come around 6-7 months after their app was received.
Once you send in your PCCs and Schedule A, it's a bit quiet until you receive the med request.