What Is IV-D Child Support and How Does It Work?

IV-D child support is the federal-state program that establishes paternity, sets support orders, collects payments, and enforces them through your state’s child support agency. The “IV-D” comes from Title IV, Part D of the Social Security Act, which requires every state to run a child support enforcement program with federal funding and federal oversight. If you applied for services through your state agency, had a case opened automatically because you receive public assistance, or were served with papers from a state child support office, your case is a IV-D case.

Where the Name Comes From

Congress created the program in 1975 to reduce public spending on welfare by making sure noncustodial parents contribute financially to their children. Every state must designate a single agency to run its IV-D program, and that agency answers to both state law and federal rules.¹ The label sticks around because the funding stream and federal requirements come attached to it.

What a IV-D Agency Does

Establishing Paternity and Support Orders

Before support can be collected, a legal parent-child relationship has to exist. For unmarried parents, that means establishing paternity, either through a voluntary acknowledgment form (often signed at the hospital) or through genetic testing when paternity is disputed. Once parentage is established, the IV-D agency or a court applies the state’s child support guidelines to set a monthly amount. The order typically covers cash support and a contribution toward the child’s health insurance.

Locating a Missing Parent

When a noncustodial parent can’t be found, IV-D agencies use the Federal Parent Locator Service, which searches databases at the IRS, Social Security Administration, Department of Defense, Department of Veterans Affairs, and other federal agencies, along with the National Directory of New Hires that tracks employment and wage data reported by employers nationwide.² A private attorney can subpoena records, but no one outside the government reaches these databases.

Reviewing and Modifying Orders

Orders aren’t permanent. Either parent can request a review when circumstances change, such as a job loss, a raise, new children, or a change in the child’s medical needs. The agency looks at current income and reapplies the state guidelines. Federal law also requires states to review orders at least every three years for families receiving public assistance.¹ A pending modification does not pause the existing obligation.

Enforcement Tools That Come With a IV-D Case

This is where IV-D matters most. A privately negotiated support order is only as strong as your willingness to pay an attorney to enforce it. IV-D agencies have enforcement mechanisms built into federal law, and they can use them without you hiring a lawyer.

Wage Withholding

Income withholding is the default collection method in IV-D cases. The agency sends an order directly to the noncustodial parent’s employer, and the employer deducts support from each paycheck before the parent sees it. Federal law caps the deduction at 50% of disposable earnings if the parent supports another spouse or child, and 60% otherwise. Both limits rise by 5 percentage points when arrears run more than 12 weeks overdue.³

Tax Refund Intercepts

The Federal Tax Refund Offset Program lets IV-D agencies intercept federal and state tax refunds to cover past-due support. If the custodial parent receives TANF, the noncustodial parent must owe at least $150 in arrears for the case to qualify. In non-TANF cases, the threshold is $500.⁴

Passport Denial

A parent who owes more than $2,500 in past-due support can be blocked from getting or renewing a U.S. passport. The state IV-D agency certifies the debt to the federal Office of Child Support Services, which forwards the name to the State Department. Paying the balance below $2,500 does not automatically remove the flag.⁵⁶

License Suspension

States must have procedures to suspend or restrict driver’s licenses, professional and occupational licenses, and recreational licenses of parents who owe overdue support or who ignore subpoenas in child support proceedings.⁷ Losing a driver’s license or a professional credential tends to get attention that paper notices don’t.

How to Apply and What It Costs

Any parent or guardian can apply for IV-D services by contacting the state child support agency. You don’t need to be low-income or on public benefits. Applications are usually available online, by mail, or in person. You’ll be asked for the child’s birth certificate, whatever you know about the other parent (name, address, employer, Social Security number), and any existing court orders.

If you receive TANF, foster care benefits, or Medicaid, your case is typically referred to the IV-D agency automatically as a condition of eligibility for those programs.¹

Federal law caps the one-time application fee at $25, and states can charge less or nothing. Families receiving TANF, Medicaid, or foster care benefits pay no application fee. There’s also an ongoing charge many people don’t know about: if you’ve never received TANF and the state has collected at least $550 on your case, it must charge an annual $35 service fee, usually deducted from support collected on your behalf. That fee cannot come out of the first $550.¹

Cooperation When You Receive Public Assistance

If you receive TANF, you’re generally required to cooperate with the IV-D agency as a condition of your benefits. Cooperation means helping identify the other parent, participating in paternity testing if needed, and assisting with enforcement. Failing to cooperate can reduce or end TANF benefits for the entire household.⁸

There’s an important exception. If cooperating would put you or your child at risk because of domestic violence, states can grant a good cause waiver. Under the Family Violence Option, a state TANF agency can waive the cooperation requirement for up to six months at a time while a safety determination is made. Tell your caseworker if this applies. The waiver exists so that pursuing child support doesn’t force contact with a dangerous co-parent.⁸

When Parents Live in Different States

Interstate cases run on the Uniform Interstate Family Support Act (UIFSA), which every state must adopt to receive IV-D funding.⁹ The core principle is “one state, one order.” The state that issued the order keeps exclusive jurisdiction as long as one of the parties or the child still lives there, and another state cannot create a competing order or modify the original one except under narrow conditions.

For enforcement, UIFSA gives IV-D agencies real shortcuts. A child support agency in one state can mail an income withholding order directly to an employer in another state without registering the order in court first, so wage garnishment can start almost immediately across state lines. When court action is needed, the order can be registered in the new state and enforced as if it had been issued there. If the other parent lives in another state, the IV-D system is realistically your only practical option. Hiring private attorneys in two states is expensive and slow.

IV-D Cases Versus Non-IV-D Cases

Not every child support case is a IV-D case. When parents hire their own attorneys and negotiate support through family court without involving the state agency, that’s a non-IV-D case. A judge still issues a court order, but the state’s enforcement machinery isn’t behind it. The practical differences:

Enforcement. A IV-D agency monitors payments, sends income withholding orders to employers, intercepts tax refunds, and pursues license suspensions or passport denial. In a non-IV-D case, the custodial parent has to go back to court and pay attorney fees for each enforcement action.
Payment processing. IV-D payments flow through the state’s centralized disbursement unit, producing a clear payment record. Non-IV-D payments may go through the disbursement unit for processing or may pass directly between parents, which can lead to disputes over what was paid.
Cost. IV-D services cost at most $25 to start and $35 per year. Private enforcement can run hundreds or thousands of dollars per motion.
Interstate reach. IV-D agencies use UIFSA’s streamlined tools across state lines. A private attorney has to register the order in the other state and litigate there.

A non-IV-D case can be converted at any time. If you have a private support order and the other parent stops paying, applying for IV-D services brings the state’s enforcement tools into your case.

Your Responsibilities Once a Case Is Open

Both parents have obligations. Custodial parents need to keep the agency updated on their address and to report anything they learn about the other parent changing jobs or moving. Noncustodial parents must report employment changes and keep paying on time even after requesting a modification.

Both parents have to attend scheduled hearings and appointments. Ignoring a notice doesn’t make the case go away. For noncustodial parents, skipping a hearing can produce a default order based on whatever income information the agency already has, which is often higher than what a proper hearing would produce. For custodial parents, failing to provide requested information slows the case to a crawl.

Support obligations typically last until the child reaches 18 or 21, depending on the state, and can extend longer for a child with disabilities or end earlier through legal emancipation. Arrears don’t disappear when the child ages out. The IV-D agency can continue collecting until the balance is paid in full.

1
Office of the Law Revision Counsel. 42 U.S. Code 654 – State Plan for Child and Spousal Support
2
Administration for Children and Families. Overview of Federal Parent Locator Service
3
Office of the Law Revision Counsel. 15 U.S. Code 1673 – Restriction on Garnishment
4
Administration for Children and Families. When Is a Child Support Case Eligible for the Federal Tax Refund Offset Program
5
Office of the Law Revision Counsel. 42 U.S. Code 652 – Duties of Secretary
6
Administration for Children and Families. Passport Denial Program 101
7
Office of the Law Revision Counsel. 42 U.S.C. 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
8
Administration for Children and Families. Dear TANF and Child Support Administrators – Cooperation Requirements and Flexibilities
9
Administration for Children and Families. 2008 Revisions to the Uniform Interstate Family Support Act