In a joint custody arrangement in New York, one parent still owes child support to the other, and it is almost always the parent with the higher income. New York’s Child Support Standards Act calculates the obligation from each parent’s income rather than the number of overnights the child spends at each home, so a 50/50 parenting schedule does not cancel the support duty. The higher earner is designated the “non-custodial” parent for support purposes and pays a percentage of combined parental income, prorated by income share, up to a $193,000 cap effective March 1, 2026.
Who Pays When Custody Is Shared Equally
The controlling case is Bast v. Rossoff, a 1998 Court of Appeals decision that answered the question many shared-custody parents ask first: if we split time evenly, does anyone owe support? The court held that child support in a shared custody case is calculated the same way as in any other case.1Justia Law. Bast v. Rossoff One parent must still be labeled non-custodial for support purposes, even when the child lives with both parents equally.
That label goes to the higher earner. If one parent earns 65% of combined income and the other earns 35%, the higher earner pays. The reasoning is practical: a child should not experience a noticeably different standard of living depending on which parent’s house they are at that week. Routing support from the higher earner to the lower earner narrows that gap.
How the Amount Is Calculated
The calculation starts with each parent’s gross income from the most recent federal tax return. The statute then allows specific deductions before the formula is applied:2New York State Senate. New York Family Court Act 413 – Parents Duty to Support Child
- FICA taxes actually paid (Social Security and Medicare).
- New York City or Yonkers income tax actually paid, if applicable.
- Maintenance paid under a court order or written agreement.
- Child support actually paid under a court order for children not in the current case.
- Unreimbursed business expenses, to the extent they do not also reduce personal spending.
- Public assistance and SSI received.
After these deductions, each parent’s adjusted income is added together to produce combined parental income. The court then applies a fixed percentage based on the number of children in the case:
- One child: 17%
- Two children: 25%
- Three children: 29%
- Four children: 31%
- Five or more: at least 35%
These percentages apply to combined parental income up to $193,000, effective March 1, 2026.3New York State Child Support Services. Child Support Standards Chart The cap updates every two years based on the consumer price index; it was $183,000 from 2024 through February 2026. For combined income above the cap, the court may apply the same percentages or use other statutory factors to decide what, if anything, to add.4New York State Senate. New York Domestic Relations Law 240 – Custody and Child Support
Once the basic obligation is set, it is split between the parents in proportion to their income shares. If Parent A earns 60% of combined income and Parent B earns 40%, Parent A is responsible for 60% of the obligation. In a joint custody arrangement, the parent designated as the non-custodial payor sends that share to the other parent.
Both parents must bring financial documentation. Family Court requires a Financial Disclosure Affidavit, and Supreme Court divorce cases use a more detailed Statement of Net Worth. Either venue will expect recent tax returns, W-2s or 1099s, and pay stubs.5New York Courts. Child and Spousal Support
A Worked Example
Say two parents share custody equally of one child. Parent A earns $120,000 after deductions and Parent B earns $80,000. Combined parental income is $200,000, but the formula applies only to the first $193,000. Seventeen percent of $193,000 is $32,810. Parent A earns 60% of the combined income, so Parent A’s share is $19,686 per year, or roughly $1,640 per month. The court could add an amount for the $7,000 above the cap, but that portion is discretionary.
When Courts Can Adjust the Formula
The formula amount is not always the final number. The statute lists ten factors a court can use to find the guideline amount “unjust or inappropriate” and deviate from it.2New York State Senate. New York Family Court Act 413 – Parents Duty to Support Child Several of these matter more in joint custody cases than in sole-custody ones:
- Extraordinary visitation expenses. If the shared custody arrangement requires the non-custodial parent to maintain a larger home or incur significant travel costs to exercise parenting time, the court can factor those costs in.
- The child’s standard of living, meaning what the child would have experienced if the parents had stayed together.
- A large disparity between the parents’ incomes.
- Tax consequences of the support arrangement for each parent.
- Non-monetary contributions, such as a parent providing significantly more hands-on care or transportation.
- The financial resources of the child, such as independent income or a trust.
This is where most joint custody disputes play out. The formula itself is mechanical, but the deviation factors give judges room to account for the real cost of maintaining two fully functional homes for the same child. If you are the higher earner in a true 50/50 arrangement, these factors are your main argument for reducing the guideline number.
Add-On Expenses the Base Amount Does Not Cover
The basic child support figure is not the whole bill. New York law requires parents to split three additional categories of cost in proportion to their incomes:2New York State Senate. New York Family Court Act 413 – Parents Duty to Support Child
- Reasonable childcare costs when the custodial parent works or attends school or vocational training that the court finds will lead to employment.
- The cost of providing health insurance for the child.
- Unreimbursed medical expenses, including co-pays, prescriptions, dental work, orthodontics, and therapy.
These are separate from the base support amount and sit on top of it. If Parent A earns 70% of combined income, Parent A pays 70% of a $500 monthly daycare bill regardless of whose week it is. Missing an add-on payment carries the same enforcement weight as missing base support.
Courts can also order parents to contribute to educational expenses, including private school tuition and college costs, until the child turns 21. That amount is discretionary, and judges weigh each parent’s ability to pay, the child’s academic ability, and the educational expectations the parents had before separating.
How Long Child Support Lasts
Child support in New York continues until the child turns 21, not 18. That is longer than most states, and it catches many parents off guard. Support can end earlier if the child becomes emancipated through:
- Marriage, which emancipates a child automatically.
- Military enlistment.
- Full financial self-sufficiency outside parental control, though the parent seeking to end support carries the burden of proving it.
Parents can agree in a separation or settlement agreement to end support at a different milestone, such as college graduation or age 22, but absent such an agreement the statutory cutoff is 21.4New York State Senate. New York Domestic Relations Law 240 – Custody and Child Support
Changing the Order Later
Life changes, and New York provides three independent grounds for revisiting a support order:6New York State Senate. New York Family Court Act 451 – Modification of Support Order
- A substantial change in circumstances. Job loss, serious illness, a child’s new medical needs, or a major shift in the custody arrangement can all qualify.
- The passage of three years since the order was entered or last modified. Either parent can request a review without showing any specific change.
- A 15% change in either parent’s gross income since the order was last set.
A voluntary income reduction does not count. If a parent quits a high-paying job or deliberately scales back hours, the court will not treat that as grounds for lowering support unless the parent proves the reduction was involuntary and they have made genuine efforts to find comparable work.6New York State Senate. New York Family Court Act 451 – Modification of Support Order Parents can also opt out of the three-year and 15% triggers in a written agreement, so check your settlement or stipulation before relying on either.
How Child Support Is Taxed
Child support payments are not deductible for the parent who pays and not taxable income for the parent who receives.7Internal Revenue Service. Publication 504 – Divorced or Separated Individuals This federal rule applies regardless of how your custody is structured. The payor should not expect any tax benefit from paying, and the recipient does not report the amounts on a tax return.8Internal Revenue Service. Publication 525 – Taxable and Nontaxable Income Spousal maintenance has different rules, and the IRS will treat any amount contingent on a child-related event as child support regardless of what the agreement calls it.