On April 1, 2026, the Ninth Circuit handed California employers a meaningful win in O’Dell v. Aya Healthcare Services, Inc., No. 25-1528. The court reversed a Southern District of California ruling that had used a procedural doctrine—non-mutual offensive collateral estoppel—to invalidate arbitration agreements for more than 250 opt-in plaintiffs based on two prior arbitrator decisions finding the employer’s agreements unconscionable.
The decision matters because it closes off a tactic that could have allowed a small number of adverse arbitration outcomes to wipe out an employer’s entire arbitration program in a collective or class action. For California employers who have invested in arbitration agreements as a risk-management tool, the ruling reaffirms a foundational principle: each arbitration agreement stands or falls on its own terms.
Here are five practical takeaways for California employers.
1. Arbitration agreements must be evaluated individually, not in bulk.
The district court in O’Dell allowed two arbitrator rulings—each involving a different employee and a different arbitrator—to preclude Aya from enforcing hundreds of other arbitration agreements signed by opt-in plaintiffs. The Ninth Circuit rejected that approach, holding that the Federal Arbitration Act requires courts to enforce arbitration agreements according to their terms and that applying non-mutual offensive collateral estoppel in this context conflicts with the FAA’s core principle of consent.
For California employers facing collective or class actions—particularly under the California Labor Code —this means that a single adverse arbitration ruling against one employee does not automatically bind the employer as to every other employee. Each agreement is its own contract, and each employee consented to arbitration on an individualized basis.
2. Delegation clauses remain powerful.
The Aya arbitration agreements contained delegation clauses that sent questions of the agreement’s validity to the arbitrator rather than the court. That structure was central to what happened next: when the initial four plaintiffs challenged the agreements, arbitrators—not judges—decided the unconscionability questions.
California employers should consider having clear, express delegation clauses in their arbitration agreements. A well-drafted delegation clause keeps gateway issues (validity, enforceability, scope) in the arbitral forum and reduces the number of issues courts can use to deny a motion to compel. O’Dell is a reminder that the architecture of the agreement—not just the substance—matters.
3. Split arbitrator results do not doom the rest of the program.
In Aya’s case, the arbitrators divided two-to-two on whether the agreements were unconscionable. The district court gave preclusive effect only to the two decisions finding the agreements invalid—turning a split into a sweeping defeat. The Ninth Circuit correctly observed that this approach transformed individualized arbitrations into something like an unauthorized bellwether class action that the parties never agreed to.
The lesson for employers: inconsistent arbitrator outcomes are a fact of life in large workforces. O’Dell confirms that adverse decisions in a handful of arbitrations are not a basis for invalidating agreements with other employees. Employers can continue to enforce their agreements on an individual basis, even when some arbitrators reach unfavorable results.
4. The ruling does not cure substantively flawed arbitration agreements.
O’Dell is a procedural win. It does not insulate employers from the substantive unconscionability challenges that remain the bread-and-butter of plaintiffs’ attacks on arbitration in California. The Armendariz factors can still apply, and California courts continue to scrutinize fee-splitting provisions, venue clauses, limitations on remedies, discovery restrictions, and presentation issues—as recent cases like Fuentes v. Empire Nissan (arbitration agreement in nearly unreadable font) illustrate.
Two of the four arbitrators in O’Dell found Aya’s agreements unconscionable because of their fee and venue provisions. That is a reminder that even a structurally sound arbitration program can be undone by one-sided terms. Employers should not read O’Dell as a reason to delay a substantive review of their agreements.
5. California employers should use this as a reminder to audit their arbitration programs.
Now is a good time for California employers to conduct a focused audit of their arbitration agreements. Key items to review include:
- Consider implementing a delegation clause assigning gateway issues to the arbitrator.
- Fee allocation consistent with Armendariz—the employer bears the costs unique to arbitration.
- A reasonable, neutral venue that does not impose unfair burdens on the employee.
- Mutual remedies and mutual coverage (both sides bound to arbitrate).
- A severability or savings clause that allows the agreement to survive if a specific provision is found unenforceable.
- Presentation that passes a readability check—legible font, clear headings, separate signature, and no buried consent.
- A carve-out framework that properly addresses PAGA and sexual harassment claims consistent with current California and federal law.
The Ninth Circuit has reaffirmed that arbitration programs built on individualized consent will be enforced on an individualized basis. Employers who pair that protection with a substantively defensible agreement are in the strongest possible position heading into the remainder of 2026.









