How to Modify Child Custody

Reviewed by DocDraft Legal Team · United States · Last updated October 7, 2026

Modifying child custody means asking the court that issued your existing custody or parenting time order to change it, because something significant has changed since the order was made. Every state allows it, but the test you must meet and the steps you take differ from state to state. Courts do not reopen custody simply because a parent is unhappy with the arrangement. Almost everywhere you must first show a change in circumstances that is substantial enough to matter, and then show that the new arrangement you are asking for is in the child's best interests. Two rules decide most of what happens next, and both are set by state law. The first is whether your state bars a modification motion for a fixed period after the last order, and what showing lifts that bar early, which is usually evidence that the child's present environment endangers them. Some states impose such a period and others impose none at all. The second is relocation: if the reason custody needs to change is that one parent is moving, most states require written notice a set number of days in advance once the move crosses a distance or a state line, and missing that notice can cost a parent the move. Which court hears the motion, whether the state publishes a modification form, and what the filing fee is also vary. Select your state below for its own standard, its waiting period if it has one, its relocation notice rule, the court and forms, and how a parent responds to a motion. DocDraft can prepare the filing, with attorney review available.