Door 1 · California
How to lower child support in California
substantial-change (change in circumstances) — no statutory numeric threshold
ESTIMATE only
The California test, in plain words
Threshold: No statutory numeric threshold — see below. (Cal. Fam. Code §§3651, 3653)
The agency screen is not a court standard. California law sets no numeric threshold for a court modification — the court route is a change of circumstances under Fam. Code §§3651, 3653. The 20% or $50, whichever is less, figure is the local agency's review screen (22 CCR §115535), and it is labeled that way everywhere on this site. Either parent may file in court at any time regardless of the screen.
Agency route: Local Child Support Agency (LCSA) / DCSS — Review and adjustment. Court route: Superior Court — Parties may file their own motion at any time regardless of the agency test
One trap to know: A stipulated below-guideline order needs no change of circumstances at all to be raised to guideline (Cal. Fam. Code §4065(d); 22 CCR §115535(a)(1)(B))
Exactness: ESTIMATE only — permanently. California is never labeled exact on this site.
Run the California checker
The kit
Child Support Modification Kit — $39, one-time
Everything the free tool points to, written out in full: walkthroughs, worksheets, letters, and trackers for your state. One payment. Yours to keep.
Track B — the evidence checklist (never scored)
- Change in circumstances (case law under §§3651, 3653)
- Evidence the change is reasonably expected to last >3 months (22 CCR §115535)
- Termination letter / unemployment filing / final pay stub for involuntary job loss
- Before/after pay stubs and employer letter for pay cut
- SSA determination / physician statement for disability
- Overnight log (12-month calendar) for timeshare change
- Health-insurance premium statements
- Dated job-search log answering involuntary + diligent attempts
Arrears firewall: a modification runs from filing or service forward — it never touches arrears that already accrued. If arrears are the problem, go to Door 2.
Sources
- CA guideline formula and K brackets — Cal. Fam. Code §4055(a), (b)(3), effective 2024-09-01 (SB 343)
- CA net disposable income — Cal. Fam. Code §4059
- CA agency screen — 22 CCR §115535; childsupport.ca.gov
- CA deviation / add-ons / hardship — Cal. Fam. Code §§4057(b), 4062, 4071, 4058(b)
Rules checked October 2026.