How Living Together Affects Child Support Payments

Pretty much everyone is familiar with the term "child support." In the past, you'd have been correct in thinking that child support boiled down to: Dad pays it, and Mom receives it. But today, the concept of child support is more complicated, thanks to developments including the dramatic increase in two-income households and a push toward balancing the amount of time each parent spends with their children. Also, more and more unmarried couples live together, including divorced parents and their new partners. Learn how that can affect the support they must pay for their children and their partners' kids.

• Parents' Duty to Support Their Children
• How Living With a New Partner Affects Child Support
• Do Unmarried Parents Have to Pay Child Support When They're Living Together?
• What Happens to Child Support If the Parents Get Back Together?
• Changing or Ending a Child Support Order
• Getting Help with Child Support Problems

Parents' Duty to Support Their Children

No matter what state you live in, both parents—whether married or not—have a legal obligation to support their children. Don't be confused by the fact that the court usually orders only one parent to make child support payments. That's because the law assumes that the custodial parent (the one the child primarily lives with) is already contributing to the child's support on a day-to-day basis, by directly providing food, clothing, and shelter.

The basics of child support—including who pays—have been fairly consistent across the states. But for many years, the dollar amount of child support a parent should pay was an educated guess at best, depending on which judge happened to be hearing the case.

In order to help judges make fair and consistent child support decisions, each state now has child support guidelines. The guidelines do differ somewhat from state to state. But generally speaking, they use a formula based on parental income to calculate the support figure. The guidelines typically take certain other factors into consideration as well, such as health insurance costs, work-related child care, and the amount of time the children spend with each parent.

States do give judges the leeway to order an amount of child support that's higher or lower than the amount calculated under the guidelines. But in order to do that, a judge almost always has to explain why strict application of the guidelines would be unjust or inappropriate under the circumstances in the particular case.

How Living With a New Partner Affects Child Support

Normally, if you remarry or live with a new partner, that won't—in and of itself—affect an existing child support order. That's because your new partner usually has no legal obligation to support your children from a prior relationship. And the child support guidelines in most states don't use a new partner's income when calculating child support.

But that doesn't mean that a new marriage or cohabitation will never have any impact on the amount of child support a parent owes.

Can Living With a New Partner Indirectly Impact Child Support?

Even in the majority of states that don't take new-mate income into account when calculating child support, a parent's new relationship could have an indirect effect on the parent's child support obligation in some circumstances. To understand how that might work, it's important to point out that child support is primarily based on a parent's ability to pay.

For example, let's say that you pay support for a child from a previous marriage and are now living with a new partner. In all likelihood, that partner will be contributing to at least some of your joint household expenses, such as utilities, maintenance, and rent. If your child's other parent files a motion (written legal request) with the court requesting an increase in child support, your state's child support guidelines might take into consideration the fact that your expenses have decreased (or at least should have done so). This means you would have more disposable income and, therefore, the ability to pay more support.

Using that same logic, if you're the parent receiving child support, and you begin living with a new partner, your child's other parent might be able to make a case for lowering child support payments based on your reduced living expenses.

Under either of those scenarios, the end result will depend on the particular circumstances of your case, as well the specifics of the guidelines in your state.

Will a New Partner's Children from a Prior Relationship Affect Child Support?

If you're living with (or married to) someone who has minor children (usually under 18 years old) from a previous relationship, that shouldn't affect your child support payments in most states—even if those kids are living with you. Again, there's ordinarily no duty to support children from a new partner's prior relationship.

Be aware that there can be exceptions, particularly if you've remarried. For example, Missouri law requires a stepparent to support a stepchild as long as that child is living in the same home. However, the law can order the natural parent to reimburse the stepparent if the stepparent's payments were needed because the natural parent failed to pay support under an existing court order. (Mo. Rev. Stat. §§ 453.400(1) and (2) (2023).) Some states require stepparents to support their stepchildren if the natural parents can't.

But if you aren't married to your live-in partner, you aren't legally considered the stepparent of your partner's children.

Will Having Children With a New Partner Affect Your Existing Child Support Payments?

In calculating child support in any particular case, state guidelines typically take into account the paying parent's legal obligation to support other children from a different relationship. This obligation will usually lower the child support amount.

So if you and your new partner have children together, you're legally obligated to support those kids. And if you're paying child support for kids from a previous relationship, you may be able to request a reduction in your current support payments to your ex.

Do Unmarried Parents Have to Pay Child Support When They're Living Together?

Considering the fact that married parents don't normally have to pay child support when they're living together, there's no reason to think unmarried parents should have to pay support in the same situation. But there are a couple of situations that might change that general principle.

One is when unmarried parents separated (or never lived together), and one of them was designated as the custodial parent in a court proceeding. If that parent received public assistance, such as Temporary Assistance for Needy Families (TANF), the noncustodial parent would be liable for child support, payable as reimbursement to the TANF program. (You can't get TANF benefits without a child support action in court.)

If the parents then begin living together, the child support requirement would likely remain in place as long as one of them is still receiving public assistance. But in this situation, custodial parents should consult with the office where they made their application for benefits. They'll need to find out whether the new living arrangement affects the assistance amount—or their ability to continue receiving benefits at all. This is important, because some assistance programs calculate benefits based on household income.

Another possible scenario is one you don't see too often. If an unmarried couple are living together and one of them refuses to contribute to expenses for the children or the household, the other parent could conceivably file a request for child support with the court. The chances of success likely hinge on the specific facts of the case and the willingness of the courts in your state to address this unusual issue. In this situation, separating from the deadbeat parent might be the easier path to getting court-ordered child support.

What Happens to Child Support If the Parents Get Back Together?

Occasionally, parents who've been living apart (or even divorced) will reconcile and begin living together again. If there's a child support order in place, it makes sense that support should end—assuming the parent who was ordered to pay support contributes to the expenses involved with raising the children and maintaining the home.

But you can't just arbitrarily stop paying child support. Until a judge changes or terminates a support order (more on that below), you're still on the hook for making the payments under the existing order.

Changing or Ending a Child Support Order

In order to change (modify) a child support order, you have to get the court's permission. Start the process by filing a motion (written legal request) with the court. Most states require that you show there's been a significant change in circumstances since the existing court order was issued. What qualifies as a significant change may vary from state to state.

Having children with a new partner would probably be considered a significant change of circumstances to warrant a modification of your existing child support order. Even without new kids, living with a new partner might qualify, depending on how much your expenses have been reduced (freeing up income to pay child support).

But be aware that courts in some states won't consider a request for a child support modification unless—after applying the child support guidelines—it would result in an increase or decrease in the current support amount by a certain percentage, usually 10 to 20 percent.

If separated parents get back together, a judge would probably consider their reconciliation a significant enough change to warrant ending child support. But it's important for the parent who's been paying support to immediately file a motion to terminate the support order. This is especially critical because most child support payments are taken out of the paying parent's wages, and employers are legally obligated to continue to withhold that money until they receive a copy of a court order telling them to stop.

Getting Help with Child Support Problems

If you're faced with a child support issue, there are a number of avenues open to you for getting assistance:

• Child support agencies. Every state has a child support services agency that you can contact for assistance. These agencies are mostly geared toward helping custodial parents get the support they're legally entitled to receive. But either parent can usually get help with a request to modify an existing child support order. And the agencies in some states will review child support orders periodically (on request or automatically if the custodial parent is receiving public assistance) to see if they qualify for a modification. On the agency websites, you can usually find answers to frequently asked questions, as well as forms for requesting services. You can also call with your questions.
• State courts. Most state judiciary websites also offer DIY resources, such as how-to articles and court forms. You can search for your state name, "courts," and "child support."
• Legal advice. Of course, you can always consult with family law attorney for advice. If you're low income, you might qualify for free or low-cost help from the legal aid office in your county.