How Michigan Calculates Child Support
Michigan uses the Income Shares model to determine child support obligations. This page explains the guidelines, formula, and key factors.
Model Type
Income Shares (MCSF General Care Equation)
Michigan applies the Michigan Child Support Formula's General Care Equation, a piecewise formula over both parents' net income, then applies the Parental Time Offset -- an exponential adjustment based on the overnight split that scales continuously, with no minimum-overnight threshold.
Sources & Verification
- The two-parent interaction case (both incomes above the Low Income Threshold, both time-shares nonzero) is verified against the formula as transcribed, but not independently cross-checked against a two-axis published table cell -- the published tables are dense enough that eyeballing a specific cell risked a transcription error rather than a genuine verification.
- Does not collect inputs for additional children from other relationships (MCSF 2.08(B) Adjustment Multiplier table) or low-income-producing-assets/potential-income (MCSF 2.01(G), 2.06).
- Health care premium and child care proration (MCSF 3.05(C), 3.06(C)) is implemented per the manual's described steps but not cross-checked against a worked example in the manual.
Income Basis & Definitions
net income (both parents)
Selects base support from MCSF schedule tables.
Source: MCSF Manual: base support scheduleNet income per MCSF definitions (gross minus taxes and mandatory deductions).
Source: MCSF Manual: net income definitionNet income of the other parent per MCSF definitions.
Source: MCSF Manual: net income definitionParenting Time Handling
Annual overnights for each parent; MCSF applies a parenting-time offset when overnights exceed threshold.
Source: MCSF Manual: parenting-time offset calculationDeductions & Adjustments
Prior or existing support obligations for other children may be deducted.
Source: MCSF Manual: other support obligations adjustment