First, yes you can file for modification, but if the prior support order was based on a written agreement which settled a divorce case, then the standard for modification is "unanticipated change of circumstance." Second, your ex can certainly counter-sue you for a portion of college tuition. Third, and more importantly, whether you should pursue your case or withdraw will depend on an analysis of the respective incomes as well as what the exact college expense you will likely be assessed with. -- David Bliven, Bronx Child Support lawyer (