My ex is responsible for providing insurance for our 2 yr old son (court order). Insurance is on and off, so when he has to go to the doctor's and I take him, I sometimes have to pay the bill. However, I found out Dec. of '07, that my son's father took him to the hospital for a flare-up of his excema. Our son is being treated for it, and he's never had a flare-up that required a hospital visit. He has been to the doctor's for it and I was instructed on how to treat it. I informed my son's father how to treat his excema by giving him a copy of the discharge papers that had instructions on it. I found out through a collections agency that there is an outstanding balance of over $600 and found out it was on my credit report. This is for treatment of his excema in the E.R June of '07. I called the Billing Dept. of the hospital he went to and learned that my son's father did in fact take him (my son's father admitted it to me as well), but did not provide proof of insurance, nor update any information. The bill was sent to an address I no longer lived at (moved from that address 2006), and of course my phone number had been changed, so it went to collections. My son's father never told me he had taken him, for I would have updated my info, and made him guarentor, since if he was going to be taking him to the hospital without me knowing, then he should be paying the bill, and certainly would have made sure that they had his insurance information, if he was covered at the time. Should I be held responsible for this bill, and suffer the consequences of it not being paid? We've been back and forth to court to fix this insurance problem and I've had to be reimbursed before the last time he pulled a stunt similar to this. But this is bigger and my credit report shows it. I'm thinking of taking him to court to sue for the amount owed and repercussions for it being on my credit report. Is this too dramatic?