DissoMaster is dead. Here's what to use instead, and what's actually 'certified.'

If you came to California family-court guideline calculations in the last twenty years, you came in through DissoMaster. It was the bench tool. Judicial officers used it. Family-law attorneys built fee structures around it. Mediators printed its worksheets and stapled them to settlement memoranda. For two decades it was, functionally, the California child-support calculator.

On March 31, 2025, Thomson Reuters discontinued it.

Later that year, in December 2025, the Judicial Council decertified the California Department of Child Support Services’ free public guideline calculator while DCSS updated it for federal tax-law changes. The two events were unrelated mechanically, but the practical effect on practitioners, and on parents trying to estimate support outside an attorney’s office, was the same: the two most-used calculators in California dropped out of certified circulation in the same year. The DCSS calculator came back, recertified, in August 2026. DissoMaster did not.

This post is about what filled the void, what didn’t, and what “certified” actually means under California law (it does not mean what most people think). It also covers how a free, transparent, statute-cited alternative: the calculator we built and run at cleancalc.io, fits the post-DissoMaster landscape.

The short version

• DissoMaster: discontinued by Thomson Reuters on March 31, 2025. No updates since its last 2024 release: nothing for the 2025 OBBBA tax changes or 2026 tax tables. It is no longer on the Judicial Council’s certified list.
• XSpouse: the most common DissoMaster replacement we hear about. Paid annual-release license (from $399 per the vendor); free to courts and government agencies.
• California DCSS Guideline Calculator: decertified by the Judicial Council on December 13, 2025 while DCSS updated it for the federal One Big Beautiful Bill Act (P.L. 119-21) tax changes; recertified in August 2026 and back online, with certification running through March 31, 2027.
• Family Law Software: long-standing alternative in the practitioner market; survived the DissoMaster sunset; subscription-priced.
• CalSupport / CalSupport Pro and FamilySoft SupportCalc: the other two certified commercial calculators.
• Free / open alternatives: what many pro se litigants and mediators-on-a-budget reach for. Our calculator is one of those; we cover the differences below.

If you stopped reading here, the operational answer is: practitioners moved to one of the four certified commercial tools, most often XSpouse; the DCSS public calculator is certified again; and free alternatives need to be evaluated case-by-case on whether the math is current and whether the underlying assumptions are disclosed.

The longer version is more interesting, because it answers a question almost nobody is asking out loud: what makes a California child-support calculator “certified,” and does it matter for what you’re trying to do?

What “certified” actually means under California law

Two pieces of authority govern recognized calculator software:

• California Family Code §3830: bars courts from using support software unless it conforms to Judicial Council standards set by rule of court, and lets the Council charge developers for testing.
• California Rule of Court 5.275: sets the standards: net-income computation under §§4058–4059, accuracy within 1% on Judicial Council test cases, a glossary and input instructions, LIA-range display, a CPA statement if the software computes taxes, and certifications that expire after a year.

This is not “AB-1058 certification.” AB 1058 is the Judicial Council’s Title IV-D-funded child support commissioner and facilitator program. Its staff happen to run calculator certification, but “AB 1058” isn’t a certification standard. §3830 + CRC 5.275 is. People (and even some bar publications) occasionally use “AB-1058 certified” as a shorthand for “Judicial-Council-certified under §3830”; the accurate phrase is the second one.

What §3830 + CRC 5.275 certification actually buys you, in practical terms:

1. Courts must accept it. In non-IV-D cases, CRC 5.275(j)(3) requires courts to let parties use any certified calculator. In IV-D (local child support agency) cases, only the DCSS calculator may be used. A non-certified calculator’s printout can still be offered, but the court can’t use that software itself under §3830.
2. A required minimum feature set. Certified calculators must handle §4058 income, §4059 deductions, the §4062 add-ons with proportional allocation, the §4057(b)(2) deferred-sale factor, and the §4055(b)(7) low-income adjustment.
3. An annual recertification cycle. Certifications expire after a year, and the Judicial Council can cut a certification short when tax or support law changes, which is exactly what happened to the DCSS calculator in December 2025. The current certifications run through March 31, 2027.
4. An accountable publisher. The publisher applies in writing, pays for Judicial Council testing, and must report every change to the software during certification. They are accountable for accuracy in a way that an open-source GitHub project simply isn’t.

The thing certification does NOT do: it does not exempt the user from §4057. California family judges retain discretion to deviate from any guideline result, certified or not, on stated §4057(b) findings. Certification means the tool computes the §4055 amount correctly; it’s §4057(a), not certification, that makes that amount presumptively correct, and §4057(b) that lets the court depart from it.

The DissoMaster sunset, in context

DissoMaster was published for decades by CFLR, later part of West / Thomson Reuters. It was a Judicial-Council-certified calculator for most of that period and was, by a wide margin, the most-deployed bench tool in California family court. Judicial officers had it on their courtroom computers. Settlement conferences ran on it. Attorneys priced consultations around the assumption that a DissoMaster printout would land on the judge’s desk.

On March 31, 2025, Thomson Reuters discontinued DissoMaster and the DissoMaster Suite. What was unambiguous was that no new statute or tax-table updates would ship after its last 2024 release, and it does not appear on the Judicial Council’s current certified list. A tool that does not get One Big Beautiful Bill Act updates is, from 2026 forward, computing the wrong federal tax liability, and therefore the wrong §4059 net.

A discontinued calculator is not just inconvenient. It is actively producing wrong numbers the moment a relevant statute or tax change lands.

What replaced DissoMaster, in practice

XSpouse is the most common DissoMaster replacement we hear about. It is sold as a paid annual-release license (from $399 per the vendor, free to courts and government agencies), oriented at family-law attorneys and mediators rather than self-represented litigants. Its feature set covers the core of what DissoMaster covered, and it was recertified by the Judicial Council in 2026, through March 31, 2027.

Family Law Software is the other long-standing entrant in the practitioner market. Subscription-priced. Differentiates on richer financial-planning integration (asset division, support-and-tax interaction modeling, post-judgment forecasting) more than on guideline math per se. Some firms moved to it after the DissoMaster sunset; others were already there.

CalSupport / CalSupport Pro and FamilySoft SupportCalc round out the certified commercial field. Both were recertified in 2026.

The DCSS Guideline Calculator is the free public option run by the California Department of Child Support Services. Pro se litigants, county self-help centers, and a substantial number of mediators rely on it, and it is the only calculator allowed in IV-D cases (where the local child support agency is involved). In December 2025 the Judicial Council decertified it while DCSS updated it to incorporate the tax changes in the federal One Big Beautiful Bill Act, P.L. 119-21; courts and child support offices used an alternate certified calculator in the meantime. DCSS resubmitted it in August 2026, and it is recertified through March 31, 2027.

The gap between “DissoMaster is gone” and “DCSS is decertified pending rework” is what made late 2025 and most of 2026 unusual: practitioners with budget moved to one of the certified commercial tools; everyone else had a noticeably smaller menu of options that ran current math.

Where free alternatives fit, and where they don’t

For pro se litigants, mediators on small budgets, attorneys triaging a quick estimate before a substantive consultation, and parents who just want to see roughly where the number will land, free calculators have always served a role. The honest assessment of that role:

• A free calculator is not a substitute for §3830 certification in litigation contexts. If a number is going on a court filing, the court is going to want, at minimum, to see the inputs and the formula, and ideally to see the worksheet from an approved tool.
• A free calculator is a reasonable way to estimate the order of magnitude before deciding whether to pay an attorney for a full computation, or to sanity-check a number an attorney produced.
• A free calculator is only as good as its statute-currency discipline. A calculator that does not say which K-table version it ships and which tax year it computes against is a black box. The number it produces could be three years old.

We built cleancalc.io inside those constraints. It runs the post-SB-343 §4055 (verbatim, see our earlier post on the K-table changes). It implements the §4058 self-employment math that most W-2-shaped calculators get wrong (see our post on §4058 for 1099 and sole-prop income). It surfaces the formula and the math, not just the number. It is free, and it does not collect personal information beyond what is required to run the calculation. It does not currently hold §3830 certification (that is a multi-step process, and we have written separately about the conditions under which pursuing it makes sense for a free public tool), and so we are explicit on every page that what we produce is an estimate, not a court-authoritative figure.

If you are a self-represented litigant, the practical workflow we suggest is:

1. Run our calculator to see where the guideline lands and to see the math.
2. Print the worksheet (it is set up to attach to Form FL-342 as Item 1’s “printout of a computer calculation and findings”).
3. Take it to a self-help center, a county family-law facilitator, or an attorney for a substantive review before filing.

If you are an attorney or mediator, our calculator is useful as a sanity check and as a client-facing visualization: the formula and the math are visible in a way that DissoMaster and XSpouse output is not, but the court filing should still ride on an approved tool.

What this means for the next year

DCSS’s calculator returning should pull most pro se traffic back to it; that is the right outcome. Even so, the free-public market has gaps that free alternatives can fill responsibly if they are explicit about what they are and what they are not. The bench-tool market now runs on four certified commercial tools (XSpouse, Family Law Software, CalSupport, and FamilySoft SupportCalc), and the disappearance of DissoMaster’s network effects means new entrants have more room to compete than they have had in twenty years.

SB 343’s K-table changes will start producing published appellate opinions in 2027 and beyond. The OBBBA tax changes will work their way through the §4059 deduction stack as the IRS issues regulations and California conforms. Whatever calculator you are running, bench tool, free public, or in-house, the things to check every quarter are: does it have the current K-table, does it use the current LIA threshold, and does it compute federal and state tax against the current tables. If the answer to any of those is no, the number it produces is not the guideline figure.

The single biggest practical change for self-represented litigants in this period was that the default mental shortcut, “go to the DCSS site, run the calculator, print the result, file it”, wasn’t available for most of 2026, from the December 2025 decertification until the August 2026 recertification. It is available again. The lesson from those months is the one above: check what certification status and tax year a calculator is running before you rely on its number, whichever calculator it is.

What this post is not

This is a survey of the California child-support calculator landscape and a walk-through of the certification framework that determines which tools count as authoritative. It is not legal advice. The choice of which calculator to rely on in a contested case is a legal-strategy decision that benefits from a licensed California family-law attorney’s input. The disclaimer in the page footer applies to every section above.

The information about DissoMaster’s discontinuation, XSpouse’s market position, the DCSS calculator’s decertification and recertification, and the §3830 / CRC 5.275 certification framework reflects publicly available information current as of the statute_as_of date in this post’s frontmatter. Specific dates and pricing for proprietary commercial tools should be confirmed with each publisher directly before relying on them for any consequential decision.