Checking my last day of health coverage - what worked for you?

I was told my coverage ends on my last day, but the letter says the end of the month. I have read a lot of threads here and could not find my exact situation. I do not want to be surprised by a bill. How did you confirm your end date?

Thanks for writing this out. I went through something close to it 8 months ago, and it got easier once I kept a simple log of every call and form.

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