Does 50/50 Custody Eliminate Child Support in Wisconsin?

Sharing your child’s time equally does not eliminate child support in Wisconsin. Under the state’s shared-placement rules, both parents still have an income-based support obligation, and the higher earner pays the difference to the lower earner. The payment only disappears when both parents earn the same amount. Equal parenting time does not close the gap between two household incomes, and the formula is written to keep the child’s standard of living roughly similar in both homes.

How Equal Placement Still Produces a Payment

Wisconsin applies its shared-placement formula whenever each parent has court-ordered placement of at least 25% of overnights, which is 92 or more days per year.¹ A true 50/50 split clears that threshold easily, so the calculation in DCF 150.035 replaces the standard percentage table used in sole-placement cases.²

The math moves through four steps.

First, each parent’s base obligation is calculated by multiplying monthly gross income by the standard percentage for the number of children: 17% for one, 25% for two, 29% for three, 31% for four, and 34% for five or more.³

Second, each base obligation is multiplied by 1.5. The 150% adjustment reflects the extra cost of maintaining two fully equipped homes for the same child, from duplicate bedrooms to two sets of clothing.²

Third, each adjusted figure is multiplied by the share of time the child spends with the other parent. In a 50/50 schedule, both multipliers are 0.50.

Fourth, the smaller result is subtracted from the larger one, and the parent with the bigger number pays the difference to the other parent.²

A Worked Example at 50/50

Picture two parents sharing one child equally. Parent A earns $6,000 per month and Parent B earns $4,000.

Parent A’s calculation: $6,000 × 17% = $1,020. Multiplied by 1.5 = $1,530. Multiplied by 0.50 = $765.

Parent B’s calculation: $4,000 × 17% = $680. Multiplied by 1.5 = $1,020. Multiplied by 0.50 = $510.

Offset: $765 − $510 = $255 per month flowing from Parent A to Parent B. Even though the child is in each home exactly half the time, Parent A writes a monthly check because the income gap did not go away.

When the Payment Actually Is Zero

Two situations collapse the shared-placement payment to nothing or close to it.

If both parents earn identical incomes, the two sides of the offset come out equal and no money changes hands. The closer the incomes, the smaller the check.

There is also a ceiling on the result. The paying parent’s shared-placement obligation can never exceed what that parent would have owed under the standard percentage without any placement credit. If the offset math produces a bigger number, the court caps it at the standard percentage amount.²

Gross income for the formula is broader than take-home pay. It includes wages, interest and investment income, Social Security disability and retirement benefits, unemployment, worker’s compensation and personal injury proceeds that replace income, veterans disability compensation, and most military housing allowances. If you have a controlling interest in a closely held corporation or partnership, undistributed business income counts too, calculated as federal taxable income plus depreciation claimed, minus a reasonable straight-line depreciation allowance.⁴ Voluntary retirement contributions and deferred compensation get added back in. The practical effect is that both parents’ real earning picture, not just their W-2 line, drives the offset.

Variable Costs Come On Top of the Base Payment

The number produced by the formula covers basic living expenses. Wisconsin separately requires the court to assign responsibility for “variable costs,” defined as reasonable costs above basic support including childcare, tuition, a child’s special needs, and activities that involve substantial cost.⁵ Travel sports fees, specialized tutoring, and therapy copays are typical examples.

In a shared-placement case, these costs are divided in proportion to each parent’s share of physical placement, so a 50/50 schedule usually means a 50/50 split of variable costs. The court can adjust for significant income disparity and for transportation costs tied to the placement schedule. The order spells out whether a given cost is paid between the parents or straight to the provider. Variable cost obligations are tracked separately from the base support payment, and a change in variable costs on their own is not enough to justify modifying the overall support order.² So even if the base offset is small, the running tab for extras can still be substantial.

Asking the Court to Depart from the Formula

Either parent can ask the court to set support above or below the formula result. The court must find, by the greater weight of the evidence, that applying the percentage standard would be unfair to the child or to either parent. Wisconsin Statute 767.511(1m) sets out the factors a judge weighs:⁶

The child’s own financial resources and the full financial picture of both parents, including any maintenance received.
Whether either parent needs the income to maintain a standard of living at or above the federal poverty level.
Support obligations to other people either parent is legally responsible for.
The cost of childcare if a parent works outside the home, or the value of full-time parenting if a parent stays home.
Extraordinary transportation costs tied to exercising placement rights.
The child’s physical, mental, and emotional health needs, including health insurance costs, and educational needs.
Tax consequences of the support arrangement for each parent.
The best interests of the child as a catch-all when the numbers alone do not capture the situation.

Deviation requests show up most often when one parent out-earns the other by a wide margin, when a child has expensive medical needs, or when parents live far apart and travel costs eat into the lower earner’s budget. The statute also allows the court to consider any factor it finds relevant, so unusual circumstances are not automatically excluded.⁶

Who Claims the Child on Taxes

Only one parent can claim the Child Tax Credit for the same child in the same year. For 2025 the credit is worth up to $2,200 per qualifying child, with an additional refundable amount of up to $1,700 for parents with lower tax liability and at least $2,500 in earned income.⁷ The full credit phases out at $200,000 of income, or $400,000 for joint filers. The child must live with the claiming parent for more than half the tax year.

When a child splits the year equally between two homes, the IRS treats the parent with the higher adjusted gross income as the custodial parent for federal tax purposes, and that parent can claim the credit by default.⁸ If the parents want the other parent to claim the credit, the default custodial parent signs IRS Form 8332 releasing the claim for a specific year or range of years, and the other parent attaches the form to each return claiming the credit. A release can be revoked, but the revocation does not take effect until the tax year after the other parent receives notice.

Many Wisconsin custody agreements alternate the credit year by year. That arrangement is purely a matter of agreement between the parents, or a court order directing the release. The IRS does not enforce state court orders about the credit directly; Form 8332 is the only mechanism it recognizes for post-2008 agreements.

Changing an Order When Things Change

A support order based on today’s incomes and today’s schedule is not locked in forever. Modifying an existing order requires a substantial change in circumstances. Wisconsin law creates a rebuttable presumption that such a change exists if 33 months have passed since the last order and the support amount is a fixed dollar figure rather than a percentage of income.⁹ A real change in the payer’s income, a change in the child’s needs, or a shift in earning capacity can also qualify, with the parent requesting the change carrying the burden of proof.

A parent who quits a job or deliberately takes a pay cut will struggle to argue for a reduction. When the court finds a parent voluntarily unemployed or underemployed without good cause, it can impute income based on earning capacity rather than actual earnings, drawing on recent work history, prior earnings, education, job skills, vocational evaluations, and the parent’s job search effort.¹⁰ So walking away from a well-paying job to lower an offset payment rarely works.

Child support in Wisconsin runs until the child turns 18, or until high school graduation or age 19 if the child is still working toward a diploma or equivalent at 18.⁶ Wisconsin does not extend support beyond 19 for college. For families with multiple children, the order does not automatically step down when the oldest ages out; a parent has to file a motion to recalculate using the percentage for the remaining number of children, and the existing payment stays in effect until the court issues a new order.

1
Wisconsin Department of Children and Families. Tools to Estimate Income and Support Amounts
2
Wisconsin State Legislature. Wisconsin Administrative Code DCF 150.035 – Determining Child Support in Shared-Placement Cases
3
Wisconsin State Legislature. Wisconsin Administrative Code DCF 150.04
4
Wisconsin State Legislature. Wisconsin Administrative Code Chapter DCF 150 – Child Support Standard
5
Wisconsin State Legislature. Wisconsin Administrative Code DCF 150.02(29) – Definitions
6
Wisconsin State Legislature. Wisconsin Statutes 767.511
7
Internal Revenue Service. Child Tax Credit
8
Internal Revenue Service. Form 8332 – Release/Revocation of Release of Claim to Exemption for Child by Custodial Parent
9
Wisconsin State Legislature. Wisconsin Statutes 767.59
10
Wisconsin State Legislature. Wisconsin Administrative Code DCF 150.03