Child Support Guides
Ten short guides to the machinery behind the numbers: how the formulas are built, how parenting time and taxes move them, and what happens when payments are missed. Every factual figure cites an official source, and each guide routes into the calculator that runs the actual math for your state.
Reviewed by SupportDecode Editorial Team Page content reviewed Sources Methodology Update log
How the math works
The moving parts inside every guideline formula: the model, the income base, and what counts.
- The three support modelsIncome shares, percentage of income, and Melson: how each works and who uses which.Read the guide
- Gross vs net incomeTexas tax charts, Georgia gross pay, Illinois conversion tables: why the base differs.Read the guide
- What counts as incomeOvertime, bonuses, self-employment, and the imputed income concept, state by state.Read the guide
Parenting time and support
How schedules are written and how the overnight math feeds the support formulas.
When payments are missed
What happens to unpaid support: interest rules and the limits on paycheck withholding.
Alimony, taxes, and changes over time
The obligations that sit next to child support, and how orders get revisited.
- Alimony and child supportWhich is computed first, how one changes the other, and the post-2019 tax rules.Read the guide
- The child tax creditThe 2026 $2,200 credit, Form 8332 mechanics, and what alternating years is worth.Read the guide
- When support can changeThe substantial-change concept, guideline refresh cycles, and the no-retroactivity rule.Read the guide
How these guides are sourced
Every consequential figure in these guides traces to an official statute, court rule, or agency publication in the source list at the bottom of each page, with the date we last verified it. Where a fact could not be verified against an official source, it was left out. The guides explain concepts; they do not give legal advice, and the calculators they link always show their own effective dates and sources.
Changelog: guides library first published with 10 guides. Material changes are dated in the update log.