Checking my last day of health coverage after 9 years as a teaching assistant

HR said my health plan continues for a bit and I do not understand how. It has been weighing on me all week. The letter is unclear about dental and vision. Did coverage match what HR said?

Dental and vision sometimes end on a different date from medical. Mine did.

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