In 2024, California rewrote its child support formula for the first time since 1992, and a second wave of changes became effective on January 1, 2026. If you pay or receive support, the number on your order may no longer match the current guideline. Parents who assume nothing has changed keep paying the old amount, and parents who stop or reduce payments without a court order can create issues and arrears that need to be addressed.
As a Sacramento child support attorney with 14+ years handling these cases across Sacramento, Yolo, and Placer counties, I give clients direct answers about where the law stands and whether their order is worth revisiting. This guide breaks down what changed under Senate Bill 343, what took effect in 2026, and the steps that protect you.
The Law Behind the 2026 Changes: Senate Bill 343
Two dates matter here, and confusing them is a common mistake: the date the original change to the core formula was made, and the date the second phase of administrative changes arrived.
The Formula Overhaul Took Effect September 1, 2024
Senate Bill 343, authored by Senator Nancy Skinner, revised the statewide uniform guideline in California Family Code Section 4055. It was the first comprehensive revision of the formula in over three decades. Courts have applied the revised guideline to child support calculations since that date.
The Second Phase Took Effect January 1, 2026
SB 343 also changed how local child support agencies determine a parent's income, and those provisions started on January 1, 2026. The California Department of Child Support Services confirmed that agencies can no longer plead presumed income when establishing an order, and that 15 revised governmental child support forms, plus the updated UIFSA judgment form (FL-530), carry a January 1, 2026, effective date.
What Changed in the Child Support Formula
The base equation stayed the same. California still calculates guideline support as CS = K[HN - (H%)(TN)], where CS is the support amount, K is the portion of combined income allocated to support, HN is the higher earner's net monthly disposable income, H% is that parent's share of custodial time, and TN is the total net monthly disposable income of both parents. What SB 343 changed is the inputs that feed that equation.
Recalibrated Income Bands and K-Factor
The percentage the formula applies to combined income depends on income bands that had not been touched since 1992. SB 343 adjusted those bands and the K-factor to reflect current wages and living costs. The result differs by household, raising some orders and lowering others depending on the specific numbers.
An Expanded Definition of Income
Family Code Section 4058 now confirms income sources that parents used to dispute. The statute includes severance pay, veterans' benefits that are not based on need, and military allowances for housing and food alongside the wages, salaries, bonuses, self-employment earnings, and investment returns California already counted.
How Add-On Costs Are Divided Now
Base support is only part of the picture. Add-on expenses often decide whether an order feels fair, and the default rule for splitting them changed.
Proportional Sharing Replaced the 50/50 Default
Under the old approach, parents commonly split add-ons like work-related childcare and uninsured medical costs equally, and many did so without knowing a more balanced option existed. SB 343 amended Family Code Section 4061 to presume these costs are shared in proportion to each parent's net income. The higher earner now carries a larger share, which matters most when the two incomes are far apart.
A Presumption That Work-Related Childcare Is Reasonable
The revised law created a rebuttable presumption that childcare costs a parent incurs to work or to obtain the education or training needed for employment are reasonable costs the other parent must help reimburse. Parents also received more time to seek reimbursement, with a 90-day window to request payment for qualifying add-ons from the other parent.
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Not Sure Whether the New Rules Change Your Payment?
The 2026 changes raise some orders and lower others, and the only way to know your number is to run your actual figures against the current guideline. I can tell you where you stand before you make a move.
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Stronger Protection for Low-Income Parents in 2026
California tied its low-income protection to a moving target: the minimum wage. That connection is why the 2026 numbers matter for anyone near the threshold.
The Low-Income Adjustment Is Now an Entitlement
SB 343 made the low-income adjustment a right for qualifying parents rather than a discretionary reduction a judge might apply. A court can still set it aside in an individual case if applying it would be unjust, but the starting point favors the low-earning parent. The adjustment reduces guideline support without entirely eliminating a parent's obligation.
The 2026 Threshold Follows Minimum Wage
The threshold equals full-time earnings at the current state minimum wage, calculated as the hourly rate multiplied by 40 hours per week and 52 weeks per year, then divided by 12. California's minimum wage rose to $16.90 per hour on January 1, 2026. That math produces roughly $2,929 in monthly income, and parents earning below that figure carry a rebuttable presumption of entitlement to reduced support.
The 2026 Shift on Income and Earning Capacity
The January 1, 2026 changes reshaped how support agencies build a case when a parent's income is not on the table. This is the piece most parents have not heard about.
Agencies Must Use Actual Income or Earning Capacity
Local child support agencies can no longer plead a presumed income figure when establishing an order. The California Department of Child Support Services directed agencies to plead a parent's actual income when it is known, and to plead earning capacity when actual income is unknown. Under Family Code Section 4058, a court shall consider earning capacity when a parent's gross income is unknown and may consider it even when income is known if doing so serves the children's best interests.
Updated Forms and Case Reviews
The Judicial Council revised the governmental child support forms to match, with the remaining revised forms effective January 1, 2026. Agencies must also review a case to determine whether additional evidence exists to establish a parent's actual income. SB 343 further requires periodic review of orders so they keep pace with changes in income, employment, and a child's needs.
What the 2026 Changes Mean for Your Existing Order
Here is the point clients care about most: none of this automatically rewrites your existing child support order. An order entered before these changes stays in force under its existing terms until a court modifies it.
The New Law Can Justify a Modification
To change your amount, you file a Request for Order (Form FL-300) asking the court to recalculate support under the current guideline. A modification requires a material change in circumstances, and the SB 343 framework can support that showing when the revised formula would produce a meaningfully different number. Whether a modification helps depends entirely on your figures, since the same change lowers one parent's payment and raises another's.
Run the Numbers Before You File
A modification can cut both ways, so calculating the likely result first protects you from filing a request that hurts your position. You can generate an estimate through the official calculator on the California Department of Child Support Services website, and I run the current guidelines for clients before we decide whether filing makes sense. Guessing wrong costs money in either direction, so weigh the filing against what a family law lawyer costs in California.
Common Mistakes Parents Make Under the New Rules
Two errors show up repeatedly, though, and both are avoidable. Knowing them saves you from an enforcement action or a payment you never owed.
Assuming the Order Updated on Its Own
Parents sometimes reduce payments believing the new formula lowered their obligation. Support does not recalculate until a court signs a new order, and paying less in the meantime creates arrears that stay collectible, subject to 10% annual interest under Code of Civil Procedure Section 685.010.
Skipping the Earning-Capacity Question
When income is disputed, or a parent is underemployed, the 2026 rules allow a court to set support based on earning capacity rather than reported income. Parents who ignore this walk into hearings unprepared to address what they could earn, not just what they claim. Documenting your actual financial picture early shapes the outcome.
Get a Direct Read on Your Support Order
California's child support rules changed in ways that affect the formula, the split of add-on costs, the treatment of low-income parents, and how agencies prove income. Whether you are establishing a first order, questioning an existing one, or facing an enforcement action, the right move depends on your specific numbers and the current guideline.
Our team at AF Law handles child support establishment, modification, and enforcement across Sacramento, Yolo, and Placer counties. I give you a straight assessment of whether the 2026 changes move your number and what filing would mean for you. Contact AF Law today to schedule your consultation.
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