Ninth Circuit Affirms Denial of LTD Benefits, Holding Prior Payment of STD Benefits Creates No Presumption of Disability and Rejecting “New Rationale” Challenge

In Mendoza v. First Unum Life Ins. Co., No. 25-3080, 2026 WL 2295887 (9th Cir. Aug. 10, 2026) (Before: Rawlinson, Sanchez, and Tung, Circuit Judges), an ERISA action challenging the denial of long-term disability (“LTD”) benefits, the Ninth Circuit affirmed the district court’s judgment upholding Defendant First Unum Life Insurance Company’s denial. Plaintiff brought suit under ERISA after Defendant denied his claim for LTD benefits, and the district court, applying de novo review, determined that Plaintiff had failed to meet his burden of proving by a preponderance of the evidence that he was disabled under the terms of the plan. The Ninth Circuit reviewed the district court’s findings of fact for clear error and its conclusions of law de novo.

The court held that the administrative record supported the district court’s determination that Plaintiff was not disabled under the plan’s terms. The record contained expert reports from both parties’ medical professionals addressing the symptoms by which Plaintiff contended he was disabled, and the district court weighed those competing assessments and found that Plaintiff had not carried his burden. The court held that this determination survived clear error review.

The court rejected Plaintiff’s argument that the district court clearly erred by crediting the testimony of Defendant’s medical professionals, who reviewed Plaintiff’s records, over that of Plaintiff’s medical professionals, who examined him in person. Citing Black & Decker Disability Plan v. Nord, 538 U.S. 822 (2003), the court noted that courts are not obliged to accord special deference to examining physicians over non-examining physicians. The court further observed that the district court had cited opinions from Plaintiff’s own experts indicating that his cognitive test performance was within normal limits, and it held that the district court’s weighing of the expert testimony survived clear error review because it was grounded in the administrative record.

The court also rejected Plaintiff’s argument that Defendant’s prior payment of short-term disability (“STD”) benefits compelled approval of LTD benefits by creating a legal presumption of disability. The court held that no such presumption exists under its caselaw and that its precedent instead treats prior payment of benefits merely as relevant evidence of disability. The district court therefore was not required to apply a presumption of disability based on the prior STD payments.

Finally, the court addressed Plaintiff’s contention that the district court clearly erred under Collier v. Lincoln Life Assurance Co., 53 F.4th 1180 (9th Cir. 2022), by upholding the denial on the basis of rationales Defendant had not raised during its administrative review, specifically arguments concerning malingering in Plaintiff’s cognitive function testing and the credibility of witness statements submitted on appeal. The court held that the district court’s reliance on these grounds was consistent with Collier because they were merely subsidiary to a pre-litigation rationale Defendant had asserted in its denial: that Plaintiff’s self-reported symptoms were disproportionate to his clinically unremarkable medical testing results. The court also held that the district court did not violate Collier when it considered differences between Defendant’s STD and LTD plans. The court affirmed the district court.