Sometimes long periods of time go by after parents separate before the custodial parent seeks financial support. The delay may arise from a noncustodial parent’s attempts to avoid responsibility or resist establishment of paternity. Pursuing retroactive support is possible when petitioning a court to order child support. When a court issues a child support order, it can determine what is owed going back to the date of separation. The income and expense guidelines to calculate child support would apply when figuring what is owed retroactively.