How to Enforce a Mediated Settlement Agreement in California After the Other Side Refuses to Sign
In California, you can often enforce a mediated settlement agreement even if the other side later refuses to sign—most commonly by moving under Code of Civil Procedure § 664.6 or relying on Evidence Code § 1123. Mediation “handshake” deals, however, are not automatically enforceable unless specific statutory requirements are met. This article explains the fastest enforcement routes, key drafting traps, and what to do when the deal was reached in mediation but signatures never materialized.
Mediation is designed to end litigation, not create a new fight over whether a deal exists. Yet a common post-mediation scenario is this: the parties agree to material terms in the mediator’s conference room, the mediator drafts a short “term sheet,” and then one side delays or refuses to sign a longer final agreement. In California, whether you can enforce that mediated settlement depends less on “fairness” and more on whether the agreement meets strict statutory requirements and can be proven without violating mediation confidentiality.
This article focuses on enforcement when the other side refuses to sign after mediation—especially where there is a signed term sheet, a writing prepared during mediation, or an oral agreement that was reduced to writing before everyone left.
1) Start with the right enforcement pathway
California offers multiple procedural routes to enforce a settlement. Choosing correctly can save months.
A. Code of Civil Procedure § 664.6 (summary enforcement in a pending case)
If there is already a lawsuit pending, the fastest tool is typically CCP § 664.6, which allows the court to enter judgment “pursuant to the terms of the settlement” if the parties stipulated in writing or orally before the court.
Key advantage: It is a motion in the existing case—usually faster and less expensive than filing a new lawsuit for breach of contract.
Key limitation: Not every mediation document qualifies. The “stipulation” must be clear, and courts often require the parties themselves (not just counsel) to have agreed in a manner that satisfies § 664.6.
B. Evidence Code § 1123 (when mediation confidentiality would otherwise block proof)
California’s mediation confidentiality rules are strict. As a rule, mediation communications are inadmissible. A settlement reached in mediation becomes provable/enforceable only if it fits within a statutory exception—most commonly Evidence Code § 1123.
Under § 1123, a written settlement agreement prepared in the course of mediation is admissible (and not made inadmissible by mediation confidentiality) if it meets specific conditions—most importantly that it is signed by the settling parties and includes language showing it is enforceable or admissible (or that it is a “settlement agreement,” among other statutory alternatives).
Practical effect: If the other side refuses to sign anything, you may lose the ability to introduce the mediation term sheet in court unless another exception applies. This is why signature mechanics at mediation are so critical.
C. A separate breach-of-contract action (slow but sometimes necessary)
If § 664.6 is unavailable (no pending case or no qualifying stipulation) and mediation confidentiality prevents using the mediation writings, a separate action for breach of contract may be the only route. This is slower and can be complicated by confidentiality rules if the “contract” was formed in mediation without satisfying § 1123.
D. Arbitration clause or enforcement provision in the MSA
Some mediated settlement agreements (MSAs) include an arbitration clause or a stipulated-judgment mechanism. If properly drafted, those provisions can create a streamlined enforcement process. The enforceability still depends on whether the underlying settlement can be proved and whether the clause itself is valid and sufficiently definite.
2) Determine whether you have an “enforceable” MSA despite refusal to sign later
When someone “refuses to sign,” the first question is: refuses to sign what? If they already signed a binding MSA or term sheet at mediation, their later refusal to sign a more formal document usually does not undo the deal.
A. Scenario 1: Everyone signed a written MSA/term sheet at mediation
If the parties signed a writing at mediation that states the essential terms and indicates it is binding/enforceable, you can often enforce it as-is. A later demand for different language in a “long form” agreement is typically treated as an attempt to renegotiate, not a condition of contract formation—unless the signed document clearly made execution of a later agreement a condition precedent.
Example: A personal injury case settles at mediation for $250,000 with a written, signed term sheet providing: “Settlement is binding and enforceable under CCP 664.6. Payment within 30 days. Mutual release and dismissal with prejudice.” If the insurer later insists on new indemnity language and refuses to pay until it’s signed, plaintiff can move to enforce the signed term sheet.
B. Scenario 2: Only the attorneys signed
For § 664.6, whether attorney signatures alone suffice depends on the posture and the wording. California courts commonly scrutinize whether the “parties” personally agreed (not only counsel), particularly when the remedy sought is entry of judgment. If only counsel signed and the client did not, enforcement becomes riskier.
Practice pointer: In mediation, obtain client signatures (and, for entities, an authorized representative’s signature with title) on the settlement writing before anyone leaves.
C. Scenario 3: Oral agreement in mediation with a later “to be drafted” document
Oral agreements made during mediation are usually not admissible because of mediation confidentiality, and they are difficult to enforce. If the deal was “we agreed in the room, but nothing was signed,” enforcement is often an uphill battle.
Bottom line: Without a signed writing that meets an exception (e.g., Evidence Code § 1123), you may be unable to prove the agreement.
3) Using CCP § 664.6 to enforce a mediated settlement in a pending case
If a lawsuit is pending, § 664.6 can be powerful. Done correctly, it can convert your settlement into an enforceable judgment.
A. What you must show
In general, you must provide the court with a settlement agreement/stipulation that is sufficiently definite and demonstrates the parties’ assent. You also must show the requested judgment matches the settlement terms.
Common items to attach:
– The signed MSA/term sheet (with all pages and exhibits)
– Any signature page(s) showing party capacity (individual, corporate officer, insurer representative, trustee, etc.)
– A proposed judgment (or order) tracking the settlement terms
– A declaration authenticating the documents and confirming the case status
B. What terms must be definite
Courts can enforce settlements when material terms are clear. Ambiguity creates delay and risk.
Material terms often include: payment amount and timing, scope of release, dismissal timing, liens (if addressed), confidentiality/non-disparagement (if included), and whether the court retains jurisdiction to enforce.
Example of a problem term: “Parties will later agree to a reasonable confidentiality clause.” If confidentiality is material, leaving it open can be treated as an unresolved essential term.
C. Court retention of jurisdiction: do it correctly
Parties often want the court to retain jurisdiction to enforce settlement after dismissal. In California, that requires careful handling—especially when dismissing the action. If the case is dismissed without proper retention, you may lose the § 664.6 “home court” for enforcement.
Practical approach: Consider deferring dismissal until performance occurs (e.g., payment clears), or use a dismissal mechanism that preserves enforcement jurisdiction if appropriate in your case.
4) Evidence Code § 1123: the mediation confidentiality gatekeeper
Mediation confidentiality can be the hidden reason enforcement fails. Parties are often surprised to learn they cannot simply submit mediation emails, mediator notes, or “what was said” as evidence.
A. Why your term sheet may be inadmissible without the right language
A writing created during mediation is not automatically admissible. To avoid being blocked by confidentiality, it must fit an exception, and § 1123 is the most frequently used for settlement agreements.
Drafting must-haves (best practice):
– It is clearly labeled as a “Settlement Agreement” or similar
– It states it is “binding” and “enforceable” (and ideally references CCP § 664.6 if a case is pending)
– It is signed by the parties (not only counsel), with capacity identified
B. If the other side refuses to sign at mediation
If the other side leaves mediation without signing, and no other exception applies, you may be unable to introduce the draft in court—meaning you may not be able to prove the settlement at all. In that scenario, the practical “enforcement” option is often to push the case forward (trial, dispositive motions) while continuing settlement pressure—unless you can establish contract formation outside mediation or through admissible evidence.
5) Step-by-step: how attorneys typically enforce when the other side won’t sign the “long form”
Step 1: Identify what document is already binding
Gather the signed term sheet/MSA and confirm whether it contains (1) essential terms, (2) binding/enforceable language, and (3) party signatures.
Step 2: Send a performance demand tied to the signed terms
Before motion practice, send a short, formal demand citing the settlement provision requiring performance (e.g., payment deadline, dismissal conditions). Attach the signed term sheet and provide a proposed dismissal/judgment packet consistent with it.
Step 3: Refuse to renegotiate beyond the signed deal
If the other side proposes new provisions (extra indemnity, broader release, new confidentiality penalties), treat them as counteroffers inconsistent with the binding agreement. Respond by offering only “ministerial” changes that do not alter substance.
