Benefits end date after a layoff (Chicago)

I am not sure what date my benefits stop after being let go as a marketing coordinator. There are 18 people counting on me, so I am trying to be careful. I do not want to be surprised by a bill. Did coverage match what HR said?

Ask HR to confirm the exact date in writing. I also called the insurance company to double-check.

I moved my appointments earlier while coverage was active. It saved me a bill.