When would my ex be able to modify custody

A modification requires a "change in circumstances" which can be one parent's move.  But, generally the move has to be substantial (150 miles is a general guideline, though less is possible).  If your move is less than 150 miles, that probably does not constitute a change justifying modification.  Even if it does, understand that joint custody (50/50 time) is deterimined based on other factors than proximity to each other.   You can follow-up if you have more specific information that you would like considered.     Donna Miller http://www.grefesidney.com/news/resources/family