Employer’s Undue Hardship Evidence Is Key in Religious Accommodation, Vaccine Mandate Case

Recently, the Ninth Circuit Court of Appeals issued a ruling in a case where a group of Washington State firefighters sued their employer for failing to accommodate their vaccine exemption requests. The firefighters claimed the only accommodation the employer offered — a leave of absence without pay — was not reasonable. In an employer win, the Ninth Circuit held that any other accommodations would have created an undue hardship, so the employer was not obligated to offer them (Petersen v. Snohomish Regional Fire and Rescue, No. 24-1044 (9th Cir. 2025)).

This case provides employers with a good example of how courts look at religious accommodation and undue hardship determinations under federal law.

COVID-19 Vaccine Mandates

Snohomish Regional Fire and Rescue (SRFR) provides fire suppression and medical services in Washington State. In 2021, 85 percent of its service calls were for emergency medical services.

In August 2021, Washington’s governor issued a proclamation requiring all Washington health care workers to get vaccinated against COVID-19. The proclamation specified that workers with sincerely held religious beliefs prohibiting vaccines could request an exemption from their employer as a reasonable accommodation. However, the law also stated that employers do not need to offer reasonable accommodations if doing so would result in undue hardship.

Out of SRFR’s 192 firefighters, 46 requested exemptions from the vaccine requirement — all of them held Emergency Medical Technician (EMT) certifications. After meeting with each of those firefighters individually, the SRFR determined no reasonable accommodation would allow the unvaccinated firefighters to continue working without causing undue hardship to SRFR’s operations.

At the same time, the firefighters’ union negotiated a Memorandum of Understanding (MOU) with the SRFR, which would allow unvaccinated firefighters who could not be accommodated (e.g., by moving into nonpublic-facing roles) to go on an unpaid leave of absence. And if they returned to work within two years, they would get priority for rehire and retain their prior rank, seniority and benefits.

Return to Work

Later, as COVID-19 hospitalizations and deaths dropped, the SRFR worked with health officials to begin inviting the unvaccinated firefighters back to work. Six months later, eight firefighters filed a lawsuit for religious discrimination. They alleged that an unpaid leave of absence was not a reasonable accommodation for their religious beliefs, and that the SRFR should have offered other accommodations, such as masks and social distancing.

The SRFR countered that they could not allow these firefighters to continue working because of the high risk that they would contract COVID-19 and transmit it among themselves and to their patients. It also didn’t have the option of providing firefighters with masks or requiring social distancing, due to the nature of their job duties. So, therefore, it could not offer any reasonable accommodation other than unpaid leave until the spread of COVID-19 had diminished. The trial court agreed with the SRFR and dismissed the firefighters’ lawsuit, but the firefighters appealed to the Ninth Circuit.

Defining Undue Hardship

The question before the Ninth Circuit was what constitutes an undue hardship. In its ruling, it stated that there is no one-size-fits-all definition — whether an accommodation creates an undue hardship depends on many factors, such as the employer’s nature, size and operating costs, as well as the comparative cost of the accommodation.

The SRFR identified three categories of undue hardship that the vaccine exemption would have cost them: health and safety costs, operational burdens and financial burdens.

On health and safety issues, the SRFR presented the testimony of a medical doctor who specialized in COVID-19. He testified that vaccinations were the best way to prevent the illness from spreading to the medically vulnerable population the firefighters served. Additionally, since the firefighters lived together in firehouses for extended periods, lack of vaccination could lead to an outbreak and reduce the availability of EMTs in the region.

The doctor also testified that social distancing wasn’t a reasonable alternative — since it could not be accomplished in patient homes or when transporting them in vehicles. And even in the firehouses themselves, one plaintiff testified that firefighters don’t always wear masks.

On operational burdens, the SRFR pointed out that when the vaccine mandate was released, it immediately received exemption requests from nearly one fourth of its workforce — a number that would severely hamper its ability to serve Washington’s residents, particularly during a time when medical calls were very high. Additionally, the SRFR faced the risk of an outbreak sidelining even more of its workforce if it allowed those employees back in the firehouse.

On financial burdens, the SRFR stated that its local prison contract required proof of vaccination for all onsite medical personnel, so it could lose that business if it could not certify that all its employees were vaccinated. Finally, the SRFR management testified that their insurer informed them that if a patient sued because they caught COVID-19 from an unvaccinated firefighter, the insurer would not cover any resulting damages.

Direct Evidence of Hardship Key to Case Dismissal

In response to the SRFR’s testimony, plaintiffs pointed to several other cases where courts found that employers failed to demonstrate that vaccine exemptions would constitute an undue hardship.

The Ninth Circuit distinguished each of those cases from the SRFR’s. In the plaintiffs’ cited cases, each employer had failed to present evidence that granting the requested accommodation would constitute an undue hardship. In contrast, the SRFR presented detailed testimony from executives and experts on the costs to health and safety (both for the employee and the general public), business operations and business finances. So, although vaccine exemptions didn’t constitute an undue hardship in the plaintiffs’ cited cases, it didn’t mean that vaccine exemptions could never result in an undue hardship to any employer.

The Ninth Circuit held that the SRFR could not have granted the plaintiffs’ proposed accommodations without undue hardship — upholding the dismissal of the firefighters’ case.

Lessons for Employers

Even though this case is specific to COVID-19 vaccine mandates, it provides a good example of how deliberate, detailed and thorough employers must be in exploring reasonable religious accommodations and making undue hardship determinations.

• Employers should always conduct an individual analysis of any religious accommodation request and document their attempts to reach a resolution.
• Demonstrating undue hardship is difficult. In this case, the Ninth Circuit pointed out that a hardship will only be “undue” if it results in significant costs to the employer — merely forcing other employees to work overtime or to swap shifts will not rise to that level. The SRFR won in part because they clearly and carefully documented the significant costs to multiple aspects of their business.
• It’s important to remember that this case was decided under federal law and that California’s Fair Employment and Housing Act (FEHA) has its own separate legal requirements and standards for religious accommodation and undue hardship. The FEHA defines undue hardship as an “action requiring significant difficulty or expense,” when considering several enumerated factors similar to what federal courts consider, such as the type and size of the employer’s operation, facilities and budget, and the proposed accommodation’s costs. While federal and state standards overlap and weigh many of the same factors, employers should keep in mind that they are different laws and work with legal counsel when considering undue hardship determinations to ensure they take both laws into account.
• Always consult with legal counsel before denying a religious accommodation or taking adverse action against an employee who claims to be exercising a sincerely held belief.