US-based retailer Costco Wholesale is facing a proposed US class action alleging undisclosed salmonella risks at a Nebraska chicken plant.

A complaint lodged in Seattle federal court claims that salmonella contamination at Costco’s chicken processing facility in Fremont was not disclosed to consumers purchasing Kirkland Signature rotisserie chicken.

Filed by Lisa Taylor of Missouri, the suit claims she bought Costco rotisserie chickens monthly and overpaid due to undisclosed contamination risks.

The lawsuit alleges the Nebraska plant “consistently” fails US Department of Agriculture safety standards.

It cites testing data indicating that more than 9.8% of whole chickens and 15.4% of chicken parts processed there were positive for Salmonella.

Costco sells its rotisserie chicken for $4.99, widely regarded as a loss-leading item designed to attract customer visits.

At its annual meeting last month, the retailer said global rotisserie chicken sales exceeded 157 million units in 2025.

The lawsuit seeks compensatory and triple damages for consumers who purchased Kirkland Signature rotisserie chicken and raw chicken parts from 1 January 2019 onward.

It alleges breaches of Washington consumer protection laws and an implied assurance that the chickens are safe to eat.

The filing follows a separate proposed class action submitted last month in San Diego federal court.

Last December, Costco Wholesale reported net sales of $65.98bn for the first quarter of fiscal 2026, which ended on 23 November 2025, up 8.2% from $60.99bn a year earlier.

In addition, the retailer filed legal action against the Trump administration seeking to halt tariff collections and recover duties paid under recently imposed global import taxes.