Legal Question in Family Law in Colorado

Without knowing exact dates, it is impossible to say for sure. For any period during which there is a court order suspending his obligation to pay, he will not have to pay any back support. Assuming everything is basically the same as before your husband received temporary custody, then the mother would be entitled to child support again from the time the child started living with her again. If your husband hasn't paid during that period, he will probably be ordered to pay for that time period. If your husband believes that the old amount is not appropriate anymore (parties' incomes have changed, the amount of parenting time he has now is different than it was before, there are extraordinary expenses that should included, cost of the child's insurance or who is insuring her has changed - it has to be something that affects the calculation), he can file a motion with the Court or go to the county's Child Support Enforcement office and ask for it to be modified. He doesn't have to wait on her. Social services cannot do it however.

If he is concerned about understanding the process, he should talk to an attorney. Also, if he doesn't like what Child Support Enforcement comes up with, he can challenge it in Court. In that case, I would definitely recommend talking to an attorney to be sure that there really are legal grounds to challenge their calculation.