Money owed that is unpaid and overdue. Generally, you will hear this term as it relates to past due child support. Your current, or on-going child support obligation does not become an arrearage until after it is overdue. When you have an arrearage, CSSD may garnish much more than your on-going amount to try to pay off the arrearage and sometimes this can get very confusing to figure out what is going on. If you have a CSSD case, they will collect the money for you. However, there are collection procedures that would allow you to get the debtor's PFD, wages etc.