How to Enforce a Mediated Settlement Agreement in California After the Other Party Refuses to Sign
In California, a mediated settlement agreement can often be enforced by motion—without a new lawsuit—if it meets Code of Civil Procedure § 664.6 or Evidence Code § 1123 requirements. Parties sometimes refuse to sign final “long-form” paperwork after mediation despite having already agreed in writing. This article explains the fastest enforcement paths, what language makes an agreement enforceable, and what to do when you only have a term sheet, email chain, or mediator’s proposal.
When a mediation ends with a handshake (or even a signed “deal memo”) and the other party later refuses to sign the formal settlement agreement, the immediate question is whether you can enforce what was already agreed—quickly, and without starting over. In California, the answer often turns on two related issues: (1) whether the settlement qualifies for summary enforcement under Code of Civil Procedure section 664.6, and (2) whether the writing is admissible despite mediation confidentiality under Evidence Code section 1119 and the settlement “admissibility” exceptions in Evidence Code section 1123.
This guide addresses the most common post-mediation breakdown: you have a written settlement document (or a collection of writings), the mediator declared an agreement, but one side is now stalling, demanding new terms, or refusing to sign the long-form agreement. The good news is that California courts regularly enforce mediated settlements when the statutory requirements are met—and they do not require the parties to later sign more paperwork if the essential terms were already agreed to in an enforceable form.
Why refusal to sign later paperwork does not necessarily defeat enforcement
Parties often memorialize settlement at mediation with a short written agreement (sometimes called a “term sheet” or “MOU”) and plan to draft a more detailed agreement later. If the writing from mediation contains the material terms and shows mutual assent, the later refusal to sign a longer document is usually treated as a breach—not proof there was no deal.
Courts distinguish between:
- A binding settlement with future documentation (enforceable), and
- An agreement to agree (not enforceable) when essential terms were left open.
Practically, enforcement is easiest when the mediation writing clearly states it is binding and enforceable, identifies the parties and claims being resolved, states the consideration (payment/terms), and includes release/dismissal terms or a clear roadmap to dismissal.
The two main enforcement tracks in California
1) Motion to enter judgment under Code of Civil Procedure § 664.6
Section 664.6 is the fastest and most common tool. It allows a court to enter judgment pursuant to a settlement agreement in a pending case. That means you can often avoid filing a new complaint for breach of contract. Instead, you bring a motion in the existing action asking the judge to enforce the settlement and enter judgment on its terms.
Key requirement: the settlement must be “in a writing signed by the parties” or an oral agreement made before the court. Post-mediation disputes often rise or fall on the “signed by the parties” element.
What counts as “signed”? Traditional wet signatures qualify, and California courts increasingly accept valid electronic signatures when they satisfy applicable rules and the parties intended to sign. But a lawyer’s signature alone is not always enough for 664.6 enforcement because the statute generally requires the parties’ signatures (not just counsel), with limited exceptions.
What relief you can get: entry of judgment or an order compelling performance (e.g., payment by a date, execution of specified releases), sometimes with enforcement provisions (interest, prevailing party fees if provided, etc.).
2) Enforcing as a contract (separate action or cross-complaint)
If you cannot meet 664.6—often because the agreement was not signed by the parties, or admissibility is blocked by mediation confidentiality—you may still pursue enforcement as a contract claim. That usually involves a new lawsuit for breach of settlement agreement (or a motion/pleading in the existing action depending on posture), and it may take longer than a 664.6 motion.
However, mediation confidentiality can prevent you from proving the contract if the only evidence is protected mediation communications. That is why admissibility under Evidence Code § 1123 and careful drafting at mediation are so important.
Mediation confidentiality: why Evidence Code § 1123 controls what can be used in court
California’s mediation confidentiality statute (Evidence Code § 1119) is broad. It generally makes writings and communications prepared for, during, or pursuant to mediation inadmissible. In other words, even if you have an email or a term sheet from mediation, you may not be allowed to use it in court unless an exception applies.
The key exception for settlements is Evidence Code § 1123. A written settlement agreement prepared in the course of mediation is admissible and enforceable if it meets statutory conditions. The safest drafting approach is to include explicit language that the agreement is enforceable and admissible.
Common 1123 “safe” features include language stating the agreement is:
- “Enforceable” or “binding,” and
- “Admissible” or “subject to disclosure,” or words to that effect, or
- Signed by the settling parties (and often their counsel), and
- Clear that it is intended to be enforceable despite mediation confidentiality.
If your term sheet lacks this kind of language, the other side may argue you cannot even introduce it into evidence. The result can be a frustrating paradox: you have a deal, but you cannot prove it with admissible evidence.
Step-by-step: how to enforce when the other party refuses to sign
Step 1: Identify what you actually have in writing
Collect and organize:
- The signed mediation term sheet/MOU (all pages, exhibits, attachments)
- Any signature pages, DocuSign certificates, or email confirmations
- Any “mediator’s proposal” acceptance writings (if used)
- Post-mediation drafts showing the deal points are unchanged
- Proof of authority if an agent signed (corporate resolutions, POA, etc.)
Then ask two threshold questions:
- Does it contain the essential terms? (Parties, payment/consideration, scope of release, dismissal, timing, and any conditions.)
- Is it enforceable/admissible under 664.6 and 1123?
Step 2: Determine whether CCP § 664.6 is available
Section 664.6 typically requires a pending case. If your mediation occurred pre-litigation, you may need to file a contract action (unless another expedited procedure applies).
If you have a pending case, check:
- Party signatures: Are the plaintiffs/defendants (not just attorneys) signed?
- Clear settlement terms: Is the agreement definite enough that a court can enforce it?
- No material conditions unresolved: If it says “subject to” later approval or later agreement on key terms, enforcement may be harder.
Step 3: Evaluate admissibility under Evidence Code § 1123
Even with signatures, you must be able to submit the document. If it was created during mediation, confirm it includes express enforceability/admissibility language or otherwise fits within § 1123. If it does not, consult counsel before filing—courts can be strict, and you do not want to bring a motion relying on inadmissible evidence.
Step 4: Send a targeted “notice to perform” letter (and build your record)
Before filing, counsel typically sends a written demand referencing the settlement terms, specifying what performance is due (e.g., “execute attached release within 5 business days,” “tender settlement funds by wire”), and offering a reasonable deadline.
This accomplishes three things:
- It may resolve the dispute without court involvement.
- It frames the other side’s refusal as nonperformance, not “no agreement.”
- It supports requests for fees/costs if your agreement provides for them.
Step 5: File the motion to enforce (or the contract action)
If 664.6 applies: file a motion to enter judgment pursuant to the settlement. Include declarations authenticating the agreement and establishing signatures, authority, and the current breach (refusal to sign long-form; failure to pay; refusal to dismiss, etc.). Attach the settlement writing as an exhibit, along with any proposed judgment.
If 664.6 does not apply: consider a breach of contract claim for the settlement agreement (or a petition or other procedural vehicle depending on the underlying dispute). Your pleading strategy must anticipate confidentiality objections and admissibility issues.
Common scenarios (and how courts tend to analyze them)
Scenario A: Signed mediation term sheet + refusal to sign the “formal agreement”
This is the strongest enforcement posture. If the term sheet includes all material terms and is signed by the parties, courts often treat the long-form document as a ministerial follow-up. The refusing party cannot usually add new terms (for example, a broader confidentiality clause, non-disparagement language, or a different release scope) as a condition to signing.
Practice tip: If you anticipate a long-form, include a clause such as: “The parties agree this settlement is binding and enforceable upon execution of this memorandum. Any subsequent long-form agreement shall be consistent with these terms.”
Scenario B: Only attorneys signed
This is a frequent problem. For 664.6, the statute generally requires party signatures. If only counsel signed, you may face an argument that 664.6 is unavailable. Depending on the facts, you may still enforce via contract theories (authority/agency), but mediation confidentiality may complicate proof if the necessary evidence is inadmissible.
