DissoMaster was commercial software, a Thomson Reuters product, that California family law attorneys and courts used for years to calculate guideline child support under Family Code section 4055 and to estimate temporary spousal support. Thomson Reuters discontinued DissoMaster as of March 31, 2025, and it is not on the Judicial Council’s current list of certified support calculators.
The law did not change with the software. California still uses one statewide guideline formula, and courts now run it through other certified programs, such as XSpouse, or the state’s free guideline calculator.
What Was DissoMaster?
DissoMaster was a support calculation program designed around California’s child support guideline. To calculate child support by hand, you need each parent’s net disposable income per month, after taxes and deductions, and then you apply an algebraic formula. Software does it in seconds.
It was widely used for years, which is why “DissoMaster” is still used loosely to mean any support printout.
Courts ran it at hearings. Each attorney used it to calculate support payments under different settlement options, and mediators used it so both parents could see the same number.
DissoMaster Was Discontinued in 2025
The Alameda County Law Library reported in March 2025 that Thomson Reuters had announced DissoMaster and the DissoMaster Suite would be discontinued as of March 31, 2025.
Certification matters here. Under Family Code section 3830, a court may use software to assist in setting child or spousal support only if it meets standards the Judicial Council adopts by rule of court. California Rules of Court, rule 5.275 sets those standards.
Certified software must compute guideline child support within 1 percent of the correct amount using default settings, and a certification generally expires one year after it is issued.
DissoMaster does not appear on the Judicial Council’s current list.
Why People Still Search for DissoMaster
Orders made before 2025 were often based on a DissoMaster printout, and those printouts still turn up in case files.
The software change does not affect an existing court order for child support. The order stays in effect until the court modifies or terminates it under Family Code section 3651.
When a parent asks to modify support, the old printout is useful as a record of the data used last time: each parent’s income, timeshare, filing status and deductions. The new calculation will be run on current software with current figures, so comparing the two printouts line by line shows what actually changed.
What Courts and Attorneys Use Now
The Judicial Council publishes the list of certified support calculators. As of this writing, it lists five, each recertified through March 31, 2027.
| Calculator | Source | Notes |
|---|---|---|
| California Child Support Guideline Calculator | Department of Child Support Services | Free of charge; the only calculator that can be used in cases handled by the local child support agency |
| XSpouse | xspouse.com | Commercial; often named as the successor to DissoMaster |
| CalSupport and CalSupport Pro | Nolotech | Commercial |
| Family Law Software | familylawsoftware.com | Commercial |
| FamilySoft SupportCalc | LegalPlus | Commercial |
The free state calculator is a good way to learn how the formula reacts to your own figures at home before you meet with a lawyer.
It gives an estimate only. The judge or child support commissioner will determine the actual order.
Because every certified program must land within 1 percent of the correct guideline amount on default settings, two programs given identical inputs should come out close together. Our California child support calculator page walks through a simplified estimate.
The Guideline Formula Did Not Change With the Software
California uses a statewide uniform guideline. Family Code section 4055 sets out the formula CS = K[HN − (H%)(TN)].
- HN is the high earner’s net monthly disposable income.
- TN is both parents’ combined net monthly disposable income.
- H% is the approximate percentage of time the high earner has primary physical responsibility for the children.
- K is the share of combined net income allocated to child support.
The result is support for one child. The statute provides multipliers for additional children. Section 4057 makes the resulting amount presumptively correct.
The Principles Behind the Guideline
Family Code section 4053 lists the principles courts apply. Both parents are mutually responsible for supporting their children, and each should pay according to their ability. The guideline seeks to place the interests of children as the state’s top priority.
The statute also says support orders should reflect California’s high standard of living and high costs of raising children. When both parents have substantial time with the children, orders should reflect the cost of two homes and minimize significant disparities in the children’s living standards in the two homes.
Timeshare is the percentage of time the child lives with each parent. Because it sits inside the equation, it can move support payments as much as earnings do.
That is why parents argue over how to count overnights and holidays. Our article on child custody and timeshare explains how the percentage is figured.
How SB 343 Changed the Guideline
Senate Bill 343 rewrote key guideline sections, and the new versions of Family Code sections 4055, 4057, 4058, 4061 and 4062 each state that they are operative September 1, 2024. Under the current text:
- The K factor uses new income bands, starting with total net income up to $2,900 a month and topping out above $15,000.
- A low-income adjustment is presumed when the paying parent’s net income is below full-time earnings at the state minimum wage.
- Child care and uninsured health care add-ons are divided in proportion to the parents’ net incomes, as adjusted for support, unless the court orders otherwise.
An order entered before that date does not change on its own. A parent who thinks the current rules would change the result generally has to file a request to modify. Read how child support is calculated in California after SB 343 for more.
What Goes Into a Support Calculation
Whatever program is used, the calculation depends on each parent’s income and the timeshare. These entries matter most.
Earnings
Wages, bonuses, commissions, self-employment earnings, rent, interest and dividends all count under Family Code section 4058.
Earning capacity can replace actual earnings. If a parent’s income is unknown, the court must consider earning capacity. If it is known, the court may use earning capacity instead after weighing the children’s best interests and the parent’s time with them.
Section 4058(b) lists factors bearing on a parent’s ability to earn, such as work history, job skills, education, health and the local job market.
Each parent’s Income and Expense Declaration (form FL-150) is usually the source of the figures.
Tax Filing Status and Dependents
The program computes taxes to reach net income, so filing status (single, head of household, married filing jointly or separately) and the number of dependents claimed change the result. Section 4059 bases the tax deduction on taxes actually payable, not current withholding.
Health Insurance and Mandatory Retirement
Family Code section 4059 allows deductions for health insurance premiums for the parent and the children the parent must support, mandatory union dues and retirement contributions required as a condition of employment, and support actually paid for other relationships.
Voluntary 401(k) contributions are treated differently from mandatory retirement. Entering one in the other’s field skews the result.
Hardship Deductions
Under Family Code sections 4070 and 4071, a judge may allow a hardship deduction, on a party’s request, for extraordinary health expenses, uninsured catastrophic losses, or the minimum basic living expenses of the parent’s children from other relationships who live with the parent.
Add-Ons for Child Care and Health Costs
Family Code section 4062 requires add-ons for child care actually incurred for employment or reasonably necessary job training, and for the child’s reasonable uninsured health care costs. Educational or special needs costs and visitation travel are discretionary.
Under section 4061, base support is figured first and add-ons are allocated after it, so look for them as separate lines.
Why Two Runs of the Same Support Calculation Can Differ
Each side often brings a printout with a different number. Usually the inputs differ, not the software.
- Base salary only versus salary plus an average bonus.
- Different timeshare percentages.
- Different filing status or dependents.
- A disputed hardship or retirement deduction.
- Imputed earnings for a parent the other side says could earn more.
- Different tax years, or an old DissoMaster run compared with a current calculation under the post-2024 guideline.
The first step is to compare the input columns line by line.
Once the parties agree on the inputs, the support calculation usually follows.
How to Read a DissoMaster or Other Support Printout
A printout looks like a wall of figures. Read it for three things, in this order.
Start with the inputs for each parent: number of children, timeshare, filing status, earnings by category and deductions. One wrong entry changes every figure below it.
Next, find each parent’s net disposable income after taxes and allowed deductions. This is where you can see whether a deduction was treated the way you expected.
Then find the guideline result: the monthly child support figure and, if one was run, a temporary spousal support figure. Note which parent pays and whether add-ons appear.
These are the same items Family Code section 4056(b) requires a court to state on request: each parent’s net monthly disposable income, federal tax filing status, deductions from gross income, and approximate timeshare. If you cannot match them to the printout, ask the person who ran it.
Temporary Spousal Support
Temporary spousal support is ordered under Family Code section 3600 while a divorce or legal separation case is pending. The Family Code sets no statewide formula for it, so practice varies depending on the county, and calculation software is commonly used to produce a starting figure.
Long-term support at judgment is different. The judge weighs the factors in Family Code section 4320, and a printout is no substitute for that analysis.
When a Judge Can Depart From the Guideline Child Support Order
Section 4057 lets a party rebut the guideline amount in limited situations, such as a qualifying stipulation or special circumstances that make the guideline unjust.
When the judge departs from guideline, section 4056 requires the court to state, in writing or on the record, the guideline amount, the reasons for the different amount, and why it is consistent with the children’s best interests.
How Support Payments Are Made Under a Child Support Order
Under Family Code section 5230, when a court orders support or changes the amount, the order must include an earnings assignment. That directs the paying parent’s employer to deduct support, plus an amount toward any arrears, from the paycheck.
The California State Disbursement Unit collects and distributes child support payments.
Frequently Asked Questions
Is DissoMaster Still Used in California?
No new calculations should be run on it. Thomson Reuters discontinued it as of March 31, 2025, and it is not on the Judicial Council’s list of certified calculators. Older printouts still appear in case files.
Is My Old DissoMaster Child Support Order Still Valid?
Yes. The software used to calculate an order does not affect whether it is enforceable. It stays in effect until a court modifies or terminates it.
How Do I Fight a Child Support Calculation in California?
Challenge the inputs. If a request for support has been filed, respond on form FL-320 with your own FL-150 and proof. To change an existing order, file a request for order on form FL-300. Do not wait: under Family Code section 3653, a modification generally reaches back only to the filing date, so a timely filing matters.
Do I Have to Pay Child Support If I Have 50/50 Custody in California?
Possibly. Equal time reduces support but does not end it. If one parent earns more, the higher earner usually still pays the other parent. When earnings and time are both close to equal, the amount can be small or zero.
When Does Child Support End in California?
Generally at 18. Under Family Code section 3901, support continues for an unmarried child who is a full-time high school student and not self-supporting, until the child finishes 12th grade or turns 19, whichever comes first. See our guide on when child support ends in California.
How Long Does Child Support Take to Arrive by Direct Deposit?
The Department of Child Support Services says payments made through the State Disbursement Unit are posted within a standard 3-day processing window. You can check payment status in the department’s Customer Connect account.
Talk With a Family Law Attorney About Your Numbers
A printout is easy to produce and easy to get wrong, whichever program produced it. It is important to check the inputs to ensure the number reflects the information provided.
Our Orange County child support lawyers can review them with you. Contact Pinkham & Associates to talk about your situation.
This article is for general educational purposes only and is not legal advice. Child support outcomes depend on the specific facts of each case and the law in effect at the time. Reading this article does not create an attorney-client relationship.
