Possibly—but not simply because the result now seems unfair. A California court may set aside a dissolution judgment when a legally recognized defect affected the judgment and the request is timely. The analysis turns on how the judgment was entered, the particular problem, when it was discovered, and what admissible evidence remains. “Reopen” is a useful search term; the court still needs a specific procedural remedy.

Start by identifying what went wrong

Find the signed, filed judgment and its attachments before deciding what to challenge. A stipulated or uncontested judgment can raise different issues from a judgment after trial. Ask:

Was there actual fraud, perjury, duress, incapacity, mistake, or a disclosure failure?
Was the problem in the agreement, the entry of judgment, service, or the court’s legal ruling?
When did the judgment enter, and when did you learn the material fact?
Is the requested change about the past judgment or only about future support, custody, or another order?

These distinctions prevent a common mistake: filing a set-aside request when the appropriate route is an appeal or a modification.

Grounds recognized in California

Family Code sections 2120 through 2129 address relief from certain stipulated and uncontested dissolution judgments. Section 2122 identifies grounds including actual fraud, perjury, duress, mental incapacity, mistake, and failure to comply with disclosure obligations. A breach of fiduciary duty or concealed material information may matter, but the moving party must connect the alleged omission to the judgment and satisfy the statute’s requirements. A general belief that the division was a bad bargain is not the same as statutory fraud or mistake.

Code of Civil Procedure section 473 can provide relief for some mistake, inadvertence, surprise, or excusable neglect. Its requirements and timing differ from Family Code section 2122. A judgment that is void for a jurisdictional or service defect can raise a different question again. The label matters less than the facts and the authority that actually applies.

How the facts may fit

Possible nondisclosure: Identify the asset, debt, income, or material fact; what was disclosed; what was omitted; when it was discovered; and how the omission affected the agreement or judgment. A later change in value, without more, is not automatically a nondisclosure.

Possible duress or incapacity: Preserve contemporaneous records showing the pressure, threats, medical condition, medication, or inability to understand the transaction. Merely regretting a signature is not proof of involuntary consent.

Possible mistake or excusable neglect: Explain the specific error, why it occurred, and why the requested relief belongs under the applicable rule. A missed deadline can require a different analysis from an incorrect legal conclusion.

Possible service or jurisdiction defect: Compare the proof of service with the actual notice received and the court’s authority over the parties. This may affect whether the judgment is void or whether another remedy applies; do not assume that an old address alone resolves the issue.

Deadlines are ground-specific

Do not rely on a universal “six-month rule.” The time limits in Family Code section 2122 vary by ground: some are measured from discovery, while others run from entry of judgment. Section 2122 also contains an outside limit for certain disclosure-based claims. Section 473 has its own limits and procedural requirements, including a six-month limit for the usual discretionary relief described in subdivision (b). A different rule may apply to a void judgment or an appeal.

Make a timeline with separate dates for service, response or default, agreement or trial, signature, entry of judgment, discovery of the alleged defect, and any later enforcement. Informal discussions, settlement negotiations, and a request for a file copy do not necessarily stop a statutory or appellate clock. Prompt review is important even when the possible deadline appears to have passed.

Set-aside, appeal, modification, or enforcement?

Problem	Usually points toward	What the proceeding addresses
The judgment was affected by a recognized fraud, perjury, duress, incapacity, mistake, or disclosure problem	Set-aside analysis	Whether the judgment or agreement should be undone or corrected under the applicable authority
The judge made a legal or evidentiary error in an appealable ruling	Appeal analysis	Error shown through the trial-court record, subject to appellate deadlines
Income, parenting circumstances, or another condition changed after judgment	Modification	Future operation of an order, not whether the original judgment was valid
A party is disobeying a valid order	Enforcement	Compliance with the existing judgment or order

Read the filed judgment and any incorporated marital settlement agreement. FL-180 identifies the judgment in many dissolution cases, but the attachments and incorporated terms can control the practical result. The page about completing the judgment process explains the judgment papers; the appeal guide addresses the separate appellate path.

Records and evidence to preserve

Organize evidence around one legal ground rather than sending an undifferentiated case file:

The complete filed judgment, attachments, settlement agreement, minute orders, and proof of service.
Preliminary and final disclosures, schedules, account statements, tax records, and the document showing the alleged omission or mistake.
Communications, drafts, translations, medical records, or witness information that bear on consent, pressure, understanding, or notice.
A dated discovery timeline and records showing what was learned and from whom.
Any transfer, collection, title, retirement-plan, tax, support, or custody consequence that occurred after judgment.

Keep original electronic files and metadata where possible. Do not backdate, alter, delete, or recreate a filed record. A persuasive request states the exact relief sought, explains why the evidence supports the ground, and addresses timeliness. The court may need to consider reliance by the other spouse or third parties, completed transactions, and the effect of undoing only part of a judgment.

What happens while relief is pending?

Filing a request does not automatically stay a judgment. Continue following existing support, custody, property, and other orders unless a court enters different relief. If collection, transfer of title, a retirement division, tax filing, or another irreversible event is imminent, ask promptly whether a stay or temporary protective order is available. Do not treat an intention to seek set-aside relief as permission to stop payments or dispose of property.

Narrow questions

Can I reopen a judgment because I changed my mind?

Usually not. Buyer’s remorse or a later disagreement with a negotiated result is not, by itself, fraud, mistake, duress, or another statutory ground. The evidence must show a legally relevant defect.

Does finding a hidden asset automatically undo the whole divorce?

No. The nature of the information, disclosure duties, discovery date, effect on the judgment, and requested remedy must be analyzed. The court may address a particular property or financial issue rather than automatically erase every term.

Does filing a set-aside motion stop enforcement?

Not automatically. Existing orders remain important until changed by the court.

What is the first practical step?

Obtain the complete court file, identify the exact defect, calculate every potentially applicable deadline, and preserve proof of discovery. The California judgment and post-judgment overview provides adjacent context without replacing a ground-specific review.

Can I set aside or reopen a California divorce judgment?