Interstate Child Support Cases: How UIFSA Works
When parents live in different states, a single federal law — the Uniform Interstate Family Support Act (UIFSA) — governs which state's court can set the order, how it's enforced across state lines, and which state gets to change it later. Every state has adopted the same version of this law, so unlike the calculation model or the termination age, the core rules here don't vary state by state.
How UIFSA Handles a Multi-State Case
One State Keeps Authority — Until Everyone Leaves
The state that issues an order keeps "continuing, exclusive jurisdiction" over it for as long as the paying parent, the receiving parent, or the child still lives there. Only once all three have moved elsewhere does authority to modify the order open up to a new state. If a parent moves but the other parent or the child stays behind, the original state still controls.
Enforcing an Order Doesn't Require Registering It First
An income withholding order can be sent directly to an out-of-state employer — no court filing or registration in that state is required, and the employer is legally required to comply. A state's child support agency can also enforce another state's order directly. Registering the order formally in the new state (there's no fee to do this under UIFSA) opens up additional tools, like license suspension, in that state.
Modifying in a New State: the "Away-Game" Rule
Once jurisdiction genuinely opens up to a new state, the parent asking for the change generally has to file in the state where the other parent lives — not their own new home state. That parent is subject to jurisdiction there simply by living there, and the moving parent is treated as voluntarily submitting to it by filing.
The Original Rules Travel With the Case
Even after another state takes over modifying an order, that state applies its own guidelines to set the new amount — but the duration of support stays governed by whichever state issued the original order. A case that started in a state where support ends at 18 keeps ending at 18, even if it's later modified in a state that would otherwise go to 21, and vice versa.
UIFSA is the same nationwide
Every state, Washington D.C., and the U.S. territories now use the 2008 version of UIFSA — New Jersey was the last to adopt it, in March 2016 — because federal law ties a state's child support funding to using this version. That means the rules above hold regardless of which two states are involved. What differs from state to state isn't the law itself, but which agency handles the case on each end — which is exactly what each state's page on this site is for.
Starting an Interstate Case
If you need child support established, enforced, or modified and the other parent lives in a different state, you don't need to file anywhere else yourself. Contact your own state's child support agency — they'll open the case, then work directly with the other parent's state agency using standardized interstate forms to locate them, establish or enforce the order, and coordinate paying and receiving support across the state line.
Find Your State's Office
Every state page on this site has that state's phone number, official website, and online case account — the same office that handles an interstate case is the one already listed there.
Browse all state child support offices →Helpful Resources
Calculator & Guidelines
See which calculation model applies once a new state takes over a case.
Learn more →When Support Ends
The original state's termination age travels with the case — see what that means for your order.
Learn more →Modify an Order
Learn how the "away-game" rule determines where to file once jurisdiction opens up to a new state.
Learn more →