State Child Support Guidelines Compared

Child support is a state-by-state system. Congress requires every state to have guidelines, but lets each state design its own. The result is dramatic variation, the same family earning the same income with the same number of children can face orders that differ by thousands of dollars per year depending on which state has jurisdiction. This guide breaks down the key differences and what drives them.

Five Largest States, Guideline Snapshot

Comparing the five most-populous IV-D programs by formula model and key parameters:

Worked Example: Three-State Comparison at $6,000/Month Income

Non-custodial parent earning $6,000/month gross, custodial parent earning $3,000/month gross, two children, no parenting-time credit. Under Texas Percentage of Income, the order is 25% of net income (after standard tax/withholding deductions); on $4,300 net, that's $1,075/month. Under California Income Shares with $9,000 combined gross, the schedule shows $1,800 total obligation and the obligor's 67% income share yields $1,206/month. Under Delaware Melson with $1,400 self-support reserve, available income is $4,600, primary need at 25% yields $1,150, and SOLA adds approximately $230, totaling $1,380/month. Spread: $305/month or $3,660/year between Texas and Delaware.

"Federal law leaves the formula choice to each state legislature, producing dramatic variation in obligations for families in identical economic circumstances." - Family Support Act of 1988

Why State Guidelines Differ So Much

Federal law (42 U.S.C. Section 667) requires states to establish child support guidelines that courts must follow as a rebuttable presumption. But the law does not dictate the formula, the income definition, or the adjustments. Each state legislature makes those choices, reflecting local economic conditions, policy priorities, and political dynamics.

The three formula models - Income Shares, Percentage of Income, and Melson - create the first layer of variation. But within the same model, states make different choices about every variable: how income is defined, what deductions are allowed, how parenting time affects the obligation, and whether healthcare and childcare costs are added on top or built in.

Key Variable: Income Definition

What it tells you: The definition of "income" for child support purposes varies more than most people realize. Some states use gross income (before taxes), others use net income (after taxes), and a few use an adjusted gross figure that falls somewhere in between. This single choice can shift a child support order by 20-30%.

What it does not tell you: Even within "gross income" states, what counts as income differs. Most states include wages, salaries, commissions, bonuses, and self-employment income. But states disagree on overtime pay (mandatory vs. voluntary), investment income, rental income, and in-kind benefits like employer-provided housing. Some states include workers' compensation and disability benefits; others exclude them.

How to use it: When reviewing child support calculations, always confirm which income definition your state uses. If you are comparing potential obligations across states (relevant in interstate cases under UIFSA), the income definition matters as much as the formula model. Check your state on PlainChildSupport to see the specific guidelines and income rules.

Key Variable: Parenting Time Credits

What it tells you: Most states reduce the child support obligation when the non-custodial parent has significant parenting time (overnights). The rationale is that a parent who has the child 40% of the time is already paying directly for housing, food, and activities during that time. However, states implement this very differently.

What it does not tell you: The threshold at which parenting time credits activate varies dramatically. Some states begin reducing support at 20% parenting time. Others require 30% or even 40% before any credit applies. A few states use a continuous formula that adjusts at every level of parenting time. In shared-custody situations (close to 50/50), the calculation methods diverge even further, some states use an offset formula, others apply a different table entirely.

How to use it: If you have or are negotiating a parenting time arrangement, understanding your state's credit threshold is critical. A difference of just a few overnights per year can mean crossing a threshold that changes the support calculation significantly. Review your state's specific approach on PlainChildSupport and discuss with your attorney how your parenting plan affects the financial obligation.

Healthcare and Childcare: Built-In vs Add-On

States handle healthcare and childcare costs through two approaches:

Built-in approach: Some states' income schedules already account for average healthcare and childcare costs. The base obligation amount assumes these expenses exist at typical levels. This simplifies the calculation but does not reflect the actual costs a specific family faces.

Add-on approach: Most Income Shares states add actual healthcare premiums and work-related childcare costs on top of the base obligation, divided proportionally between parents. This creates a more accurate order but makes the calculation more complex and the obligation less predictable.

Extraordinary medical expenses (orthodontia, therapy, chronic conditions) are handled separately in nearly every state, typically split proportionally. But states differ on what qualifies as "extraordinary" versus routine, and whether court approval is required before incurring the expense.

Income Caps and Floors

Every state's guideline has practical limits on both ends of the income spectrum:

Income caps: Most state schedules top out at a specific combined income level, commonly $15,000-$30,000 per month. For families above the cap, courts have discretion to set support based on the child's needs, the parties' standard of living, or other equitable factors. High-income cases are among the most litigated in family law precisely because the guidelines provide less structure.

Self-support reserves: Most states protect a minimum amount of income for the obligor to live on, typically pegged to the federal poverty level or a percentage of it. If applying the guideline formula would push the obligor below this floor, the obligation is reduced or set to a minimum amount (often $50-100 per month). The Melson Formula states build this concept directly into their three-step calculation.

Low-income adjustments: Several states have separate schedules or reduced percentages for low-income obligors, recognizing that applying the standard formula to someone earning $1,500 per month produces an unrealistic obligation. These adjustments vary widely, some states simply cap the obligation at a percentage of income, while others use a different formula entirely below a certain income level.

Practical Framework: Understanding Your State's Approach

Step 1, Identify your state's formula model. Start with the basics: does your state use Income Shares, Percentage of Income, or Melson? This determines the fundamental structure of the calculation. See our formulas explained guide.

Step 2, Check the income definition. Is your state gross-income or net-income? What specific income sources are included and excluded? This affects the base number everything else is calculated from.

Step 3, Understand parenting time adjustments. What is the threshold for credits in your state? How does your current or proposed parenting schedule map to the credit structure? Even small changes in overnights can cross thresholds.

Step 4, Identify add-ons. Are healthcare and childcare costs built into the schedule or added on top? If added on, how are they split? Understanding this prevents surprises when the final order includes costs beyond the base amount.

Step 5, Know the deviation factors. Every state allows courts to deviate from guidelines under specific circumstances, read our deviation factors guide to understand when and how courts adjust orders.

Frequently Asked Questions

Every figure on PlainChildSupport is rendered directly from official state guidelines and federal enforcement data, no number is typed in by an editor. This page draws directly on official state guidelines and federal enforcement data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.