Just because the insurance is in your name does not mean you have to pay the bills! Unless you have signed something at the hospital or doctors office agreeing to pay for the bills.
We left the girls on our insurance, but when they turned 18, I called the medical and dental offices in our town that we normally used and had them moved off our family account and put on their own.
I told both girls I would pay the copay for 2 Appts for cleaning their teeth, a yearly physical, Appts for getting/staying on birth control. And, if they wanted to return for mental health appointments, monthly Appts. The copay is $30 per appointment.
You are not legally responsible for his medical bills. Ksm