My X husband went to the Dr n said he was insured under my ins the ins denied the claim as I responsible???

No, you have your divorce papers? Send the office a copy if it becomes necessary
Not if he wasn't covered under your insurance.


Answer:
Only if the divorce decree states that you must carry insurance on him. For example if he is not working and has primary custody of the children, some agreements state that the spouse is to carry health insurance. In that case, yes you'd be liable to pay 1/2 of the medical expenses. If your decree states no such provision, you are not liable for any expenses.
Yes, unless you removed him from your insurance! When divorcing you have to take the spouse off your insurnace otherwise they can still be on it. Divorce papers mean nothing unless you took his name off with the insurance co.
call the insurance company and tell them to make sure your x isn't under your insurance. if he tries again, ask a lawyer if you could do something about him wrongly using your insurance w/o permission.
No, he is an adult and responsible for his own bills.
nope he received the service and supplied false insurance info. its all on him
No the insurance company said so, they said it was denied. He is responsible.
It depends.

If your divorce required you to insure him, and you failed to do so, then yes, you are responsible.

Otherwise, no, you are not responsible, not to your insurance, not to your ex, not to the doctor.