How child support is calculated

# New York: Child Support Standards Act (Family Court Act 413; the same text is Domestic
# Relations Law 240(1-b), used in divorce cases). A percentage of combined parental income
# (after FICA) up to a cap, split by income share.
# The cap and the low-income amounts change on 1 March; they are parameters, so the formula
# below doesn't need a new version when they move.
jurisdiction: us/ny
name: New York
inherits: us

x-statute: &statute
  title: "NY Family Court Act § 413"
  url: https://www.nysenate.gov/legislation/laws/FCT/413
  checked: 2026-11-02
  primary: true

x-drl: &drl
  title: "NY Domestic Relations Law § 240(1-b)"
  url: https://www.nysenate.gov/legislation/laws/DOM/240
  checked: 2026-11-02
  primary: true

x-health: &health
  title: "NY Family Court Act § 416"
  url: https://www.nysenate.gov/legislation/laws/FCT/416
  checked: 2026-11-02
  primary: true

x-custodial: &custodial
  title: "NY Courts, CourtHelp: Child Support (who is the custodial parent)"
  url: https://www.nycourts.gov/help/family-issues-divorce/child-support
  checked: 2026-11-02
  primary: true

# Case law on who the custodial parent is. The opinions from before 2003 are not on the court
# system's reporter site; their text is the official report's, as published by the Caselaw Access
# Project (Harvard Law School Library).
x-bast: &bast
  title: "Bast v. Rossoff, 91 N.Y.2d 723, 728 (Court of Appeals 1998)"
  url: https://static.case.law/ny-2d/91/html/0723-01.html
  checked: 2026-11-02
  primary: true

x-baraby: &baraby
  title: "Baraby v. Baraby, 250 A.D.2d 201, 204 (3d Dept 1998)"
  url: https://static.case.law/ad2d/250/html/0201-01.html
  checked: 2026-11-02
  primary: true

x-barr: &barr
  title: "Barr v. Cannata, 57 A.D.3d 813, 2008 NY Slip Op 10109 (2d Dept 2008)"
  url: https://www.nycourts.gov/reporter/3dseries/2008/2008_10109.htm
  checked: 2026-11-02
  primary: true

x-carlino: &carlino
  title: "Matter of Carlino v. Carlino, 277 A.D.2d 897 (4th Dept 2000)"
  url: https://static.case.law/ad2d/277/html/0897-02.html
  checked: 2026-11-02
  primary: true

x-rubin: &rubin
  title: "Rubin v. Della Salla, 107 A.D.3d 60 (1st Dept 2013)"
  url: https://static.case.law/ad3d/107/html/0060-01.html
  checked: 2026-11-02
  primary: true

versions:
  - validFrom: 2025-03-01
    nextReviewDue: 2027-03-01 # self-support reserve and poverty amount are revised every 1 March
    sources: [*statute, *drl, *health, *custodial, *bast, *baraby, *barr, *carlino, *rubin]
    notes:
      - "Deductions from income not modeled: unreimbursed employee business expenses, maintenance paid to a spouse who is not a party, maintenance paid to the other parent (deducted only when the order or agreement provides a child support adjustment for when it ends), child support actually paid for other children, public assistance, SSI, and New York City or Yonkers income taxes (FCA § 413(1)(b)(5)(vii)(A) to (G))."
      - Social Security and Medicare are computed as an employee pays them; self-employment tax is not modeled.
      - Cash medical support when the children have no health insurance and are on Medicaid or the state child health plan is not modeled. It is capped at 5% of the paying parent's gross income or that parent's income above the self-support reserve, whichever is less (FCA § 413(1)(c)(5)(iii) and (iv)).
      - Education costs and child care while the custodial parent looks for work are added at the court's discretion (FCA § 413(1)(c)(6) and (7)); not modeled.
    steps:
      - id: income
        step: gross_income
      - id: fica
        step: minus_fica
        source: { <<: *statute, section: "FCA § 413(1)(b)(5)(vii)(H) and DRL § 240(1-b)(b)(5)(vii)(H), FICA paid" }
        fica: { param: us.fica }
      - id: combine
        step: combine_incomes
      - id: custodial_parent
        step: ny_custodial_parent
        # The custodial parent has physical custody the majority of the time, counted in overnights
        # (Bast at 728; Rubin). With equal time, the parent with the greater pro rata share of the
        # obligation is the noncustodial parent (Baraby at 204; Barr; Carlino; recognized in Rubin).
        source: { <<: *baraby, section: "at 204: with equal time, the parent with the greater pro rata share pays" }
        daysInYear: 365
        equalWithinDays: 1 # 182 and 183 days: "equal, or essentially equal" (Rubin)
      - id: basic
        step: percentage_of_combined_income
        source: { <<: *statute, section: "FCA § 413(1)(b)(3) and (1)(c)(2) and DRL § 240(1-b), percentages and the cap" }
        annualCap: { param: ny.cssa.combined_income_cap }
        percentages: { "1": 0.17, "2": 0.25, "3": 0.29, "4": 0.31, "5": 0.35 }
        topIsMinimum: true # "no less than thirty-five percent ... for five or more children"
      - id: low_income
        step: ny_low_income_adjustment
        source: { <<: *statute, section: "FCA § 413(1)(d) and DRL § 240(1-b)(d), low income" }
        selfSupportReserve: { param: ny.cssa.self_support_reserve }
        povertyGuideline: { param: ny.cssa.poverty_guideline }
        belowPovertyMonthly: 25
        belowReserveMinimumMonthly: 50
      - id: add_ons
        step: prorated_add_ons
        source: { <<: *statute, section: "FCA § 413(1)(c)(4), (5) and (d), DRL § 240(1-b)(c)(4), (5), child care and health insurance" }
        # 413(1)(d): the $25 obligation names no add-ons; above it, child care, health and
        # education are added "in addition to any amounts that the court may, in its discretion, order".
        afterLowIncome: { poverty: none, reserve: discretionary }
        # FCA 416(d): not reasonable in cost below the reserve; presumed reasonable up to 5% of combined gross income.
        reasonableCost: { selfSupportReserve: { param: ny.cssa.self_support_reserve }, presumedShareOfCombinedGross: 0.05 }
      - id: not_in_formula
        step: inputs_not_in_formula
        source: { <<: *statute, section: "FCA § 413(1)(b)(5)(iii)(I) and (vii)(B), (C), maintenance" }
        inputs:
          spousalSupport: Spousal support entered is not used. New York deducts maintenance paid to the other parent, and counts it as income of the parent who receives it, only when the order or agreement provides a specific child support adjustment for when the maintenance ends (FCA § 413(1)(b)(5)(iii)(I) and (vii)(C)); maintenance paid to a spouse who is not a party is deducted ((vii)(B)). Neither is modeled.