
Quoting
Mr. Knowitall
The child custody order is out of what state? The child custody order assigns what responsibility for uninsured medical bills? If the mother's not paying her court-ordered share, dad can seek recourse through the custody court.
I haven't found any authority making a parent responsible for payment for medical care contracted for by the other parent, but that doesn't mean that it's not out there somewhere. States typically do allow collection for a minor child's medically necessary care against the parents.