Woo: Repeated Pension Assurances and Ambiguous Plan Terms Supported Continued Participation

After years of pension confirmations, a letter saying you were never eligible can put your retirement plans in doubt. Sarah Woo faced that problem after transferring between Kaiser jobs in California. In Woo v. Kaiser Foundation Health Plan, Inc., No. 23-cv-05063-RFL (N.D. Cal. Jan. 26, 2026), the court ruled for her on an ERISA equitable-estoppel claim—a claim seeking to hold the plan to its earlier representations. The result depended on repeated assurances, her reliance and an ambiguity in the plan’s allocation of eligibility authority.

A transfer changed the pension terms, but the confirmations continued

Woo began working for Kaiser in Southern California in 2002 and became a union-represented pharmacist in 2005. On June 7, 2009, she transferred to a Northern California position represented by a different pharmacists’ guild. A plan supplement excluded employees hired or transferred into that group on or after June 1, 2009, effective January 1, 2010. The applicable collective bargaining agreement instead provided for a 401(k) arrangement with employer contributions.

But Vanguard, which administered the supplemental retirement component, sent Woo an eligibility letter and enrollment kit after the transfer. She enrolled and made after-tax contributions, as the history in Woo explains. Later, the retirement service center repeatedly told her she was an active participant. A 2018 service breakdown reported 11.78 years of credited service under the Kaiser Permanente Employees Pension Plan and 3.96 under the Southern California pharmacists’ plan. The credited-service figures continue in Woo.

Only in December 2020 did a data-quality audit lead Kaiser to tell her she had been permitted to contribute by mistake. It stopped her supplemental contributions and said she should receive her contributions and associated earnings back. Woo submitted a pension claim and appealed its denial before suing. Her claim concerned continued participation in the pension arrangements, not merely the amount of a refund. Woo describes the claim and appeal.

Five requirements tied the remedy to the record

The court applied Renfro v. Funky Door Long Term Disability Plan, 686 F.3d 1044, 1054 (9th Cir. 2012). Woo had to establish a material misrepresentation; reasonable and detrimental reliance; extraordinary circumstances; ambiguous plan provisions; and representations involving an interpretation of the plan. Under Gabriel v. Alaska Elec. Pension Fund, 773 F.3d 945, 956 (9th Cir. 2014), the remedy could not contradict unambiguous written plan provisions.

Judge Rita F. Lin evaluated the administrative record on the parties’ motions for judgment under Rule 52. This was a decision making factual findings and legal conclusions on the record, rather than a ruling that allegations alone were sufficient. Woo identifies the five requirements and applies them to Woo’s evidence.

Unqualified eligibility statements differed from estimates with disclaimers

Kaiser had directed employee communications through Vanguard and the retirement service center. Applying the apparent-authority reasoning of Salyers v. Metro. Life Ins. Co., 871 F.3d 934, 940–941 (9th Cir. 2017), the court attributed their eligibility representations to the responsible Kaiser entities. Employees were reasonably led to understand that these were the channels authorized to communicate plan determinations.

The court distinguished the communications carefully. The 2018 benefit estimates expressly said they were estimates and did not guarantee benefits to someone ineligible under the plan. Those documents were not misrepresentations. Other communications confirmed active eligibility without qualification. The original 2009 letter was true when sent, but its forward-looking assurance became a misleading half-truth without a correction when eligibility purportedly changed. Later calls and the credited-service statement reinforced that assurance. Woo and the following pages explain why the source, wording and qualifications mattered.

The reliance was about career and retirement planning

Woo’s claim materials showed that continuing pension participation was a high priority in deciding whether to transfer. She remained with Kaiser and planned for retirement over more than a decade while receiving repeated confirmations. The court found that a proposed corrective 401(k) contribution did not cure that reliance: She was being asked, later in her career, to shift a decade’s planning into a different retirement arrangement.

The repeated misrepresentations over that lengthy period also supplied the extraordinary circumstances required for this claim. Woo connects the record to those findings. The decision depended on the pattern and actual reliance shown, rather than treating an account statement as a pension guarantee by itself.

The ambiguity concerned who could reverse an eligibility determination

The plan assigned the participating employer responsibility for deciding whether someone was an eligible employee and called its determination “conclusive and binding on all persons.” A different provision gave the plan administrator authority to interpret plan documents and determine benefit entitlement. Kaiser argued that the latter authority allowed it to correct the earlier mistake.

The court found another reasonable reading: The employer decided participation eligibility, while the administrator determined benefits under the plan. Reading the administrator’s authority to override the employer’s decision could deprive the binding-eligibility provision of effect. The ambiguity concerned how those provisions interacted, not whether the supplement contained an exclusion.

The court drew on Spink v. Lockheed Corp., 125 F.3d 1257, 1262–1263 (9th Cir. 1997), which likewise addressed eligibility restrictions alongside statements made final by plan language. On this reading, holding Kaiser to its earlier determination gave effect to the written terms. Woo develops that reasoning and distinguishes a different case involving an overpayment contrary to unambiguous benefit provisions.

The court granted Woo’s motion for judgment

The court found all five requirements established, granted Woo’s motion and denied the defendants’ motion. It directed the parties to submit a proposed judgment consistent with the order. The participation relief rested on the estoppel claim. Woo’s separate argument about when the exclusion amendment was validly adopted was unnecessary to resolve; the court assumed its validity for this decision, as explained in the footnote in Woo.

For another employee, the useful comparison includes the actual plan clauses, the authority behind each communication, its disclaimers and the decisions made in reliance on it. Our guide to a reversed pension-eligibility determination focuses on that review. A transfer of pension payments to an insurer raises a different issue, addressed in our pension-transfer guide.