by Kolin Tang, Matthew P. Suzor, and Cameron Smith

Two recent decisions from the Ninth Circuit—Detwiler v Mid-Columbia Medical Center, 156 F.4th 886 (9th Cir. 2025) and Peterson v. Snohomish Regional Fire Rescue, 150 F.4th 1211 (9th Cir. 2025)—offer important guidance on how courts may evaluate religious discrimination claims under Title VII of the Civil Rights Act of 1964. Together, this pair address two prongs of the religious-accommodation framework— (1) the applicant or employee’s burden of proving discrimination on its face and (2) the shifting burden on an employer to prove that any reasonable accommodation would impose an undue hardship on its business. In both instances, the Ninth Circuit Court of Appeals affirmed the district courts’ decisions in favor of the employer and signaled a more thorough and evidence-based approach to evaluating religious discrimination claims, especially in the context of COVID-19 workplace policies.

Detwiler: Distinguishing Religious Beliefs from Secular Motivations

In Detwiler, the Ninth Circuit Court of Appeals examined the initial question for any religious accommodation claim—whether the employee’s conflict with an employment duty arises from a bona fide religious belief. Although courts are historically cautious about scrutinizing the nature of religious beliefs, Detwiler illustrates that a court may look closely at whether the asserted belief is religious or grounded in secular reasoning.

On September 28, 2021, Sherry Detwiler, then a “Privacy Officer and the Director of Health Information” for Mid-Columbia Medical Center (“MCMC”) and a practicing Christian who professed that she has a religious duty to avoid consuming substances that the Bible explicitly condemns or that could potentially cause physical harm to her body, sought a religious exemption from her employer’s COVID-19 vaccine mandate. Ms. Detwiler believed from online sources that the COVID-19 vaccine was created in part from fetal cell lines. MCMC approved Ms. Detwiler’s exemption from the vaccine, but still required Ms. Detwiler to wear personal protection equipment and submit to weekly antigen testing for COVID-19, a process that involved inserting a cotton swab dipped in ethylene oxide into her nostril.

Based on her online research into ethylene oxide, Ms. Detwiler determined that ethylene oxide was harmful and therefore against her religious beliefs. After requesting that she be further exempted from the weekly antigen testing, MCMC denied her request and placed her on unpaid leave before terminating her in December 2021 after she also refused MCMC’s offer to be reassigned to a different role.

Ms. Detwiler filed suit against MCMC and other MCMC employees, seeking damages for religious discrimination in violation of Title VII and Oregon’s parallel anti-discrimination statute.  After three rounds of pleading, the district court dismissed Ms. Detwiler’s suit with prejudice, finding that her “specific determination of what is harmful . . . was not . . . premised on the Bible or any other religious tenet or teach, but rather on her research-based scientific medical judgments.”

The Ninth Circuit’s Findings

The Ninth Circuit affirmed.  Its analysis rested on determining whether Ms. Detwiler’s belief was religious or secular. The Court of Appeals noted that, to prevail on a religious discrimination claim, a plaintiff need not establish that her beliefs are consistent, widely-held, or even rational. Nevertheless, a plaintiff must connect the requested exemption with a truly religious principle.

The Court of Appeals found that Detwiler’s objection to testing did not stem from her religious belief that her “body is a temple.” Instead, it came from her personal interpretation of online health information. The court explained that Detwiler failed to show that her belief was religious in nature because she could not connect her objection to any theological principle. Her belief in the harmfulness of ethylene oxide was secular, even if she sincerely held it. In other words, Ms. Detwiler failed to demonstrate a bona fide religious conflict with her job duties.

To illustrate the point, the court offered an analogy: an employee who believes that her body is a temple may choose to exercise daily as a matter of religious practice. However, if the employee chooses to exercise in the morning based on secular research that morning workouts are most effective, the specific timing of the exercise is not a religious belief. Similarly, Ms. Detwiler’s religious belief did not meaningfully motivate her objection to antigen testing; instead, her secular research that ethylene oxide is harmful did.

Petersen: What Constitutes Undue Hardship?

While Detwiler focused on the plaintiff-employee’s burden of establishing a religious belief, Petersen examined the employer’s responsibility to prove undue hardship once an employee has established a prima facie case of employment discrimination. This decision followed the Supreme Court’s 2023 ruling in Groff v. DeJoy, 600 U.S. 447 (2023), which clarified that undue hardship exists only when the burden on the employer would be substantial and realistic. Specifically, once the employee has made a prima facie claim of employment discrimination, the burden of proof shifts to the employer.

In Petersen, eight firefighters filed a lawsuit alleging that their employer, Snohomish Regional Fire and Rescue (“SRFR”), failed to accommodate their religious beliefs when it denied their requests for exemption from the COVID-19 vaccination. In 2021, SRFR, in response to mandate by the Governor of the State of Washington, Jay Islee, requiring healthcare providers to be vaccinated against COVID-19, issued a vaccine mandate to all its firefighters.

46 out of SRFR’s 192 firefighters, all of whom also served in emergency medical technician positions (“EMT”) and held EMT or paramedic certifications, requested religious exemptions from the mandate. After extension negotiations involving the firefighters’ union, the fire department denied the requests, concluding that having unvaccinated firefighters would jeopardize its operations, public health, and safety. Many of the objecting firefighters returned to work after May 2022.

SRFR moved for summary judgment, arguing that the firefighters’ exemptions could not be accommodated without undue hardship.  The district court granted the motion.

The Ninth Circuit’s Findings

The Ninth Circuit agreed. The Court of Appeals evaluated SRFR’s health and safety costs, operations burdens, and financial burdens in determining whether exempting firefighters from the vaccine mandate would impose an undue hardship.

SRFR demonstrated that its firefighters frequently worked as EMTs and paramedics, which involved trips to local medical centers. SRFR argued, and the court agreed that allowing a substantial number of unvaccinated firefighters to continue work in this capacity could lead to severe COVID-19 outbreaks. Furthermore, such outbreaks would likely disrupt operations by having firefighters on sick leave and therefore compromise its emergency response capacity. SRFR also faced financial consequences, including the potential loss of a $400,000 annual EMS contract with the Department of Corrections and exposure to liability for virus transmission.

This combination of health, operational, and financial consequences persuaded the court that accommodating the firefighters’ request would impose a substantial burden.

How Do the Decisions Shape Religious Discrimination Law?

Detwiler and Petersen illustrate the Ninth Circuit’s increasing attention to the burdens of proving or disproving religious discrimination. Detwiler marks the adoption of a stricter standard than other circuit courts that have determined that a religious accommodation that turns upon secular considerations does not negate its religious nature. See, e.g., Thornton v. Ipsen Biopharmaceuticals, Inc., 126 F.4th 76 (1st Cir. 2025); Barnett v. Inova Health Care Servs., 125 F.4th 465 (4th Cir. 2025); Passarella v. Aspirus, Inc., 108 F.4th 1005 (7th Cir. 2024); Ringhofer v. Mayo Clinic, Ambulance, 102 F.4th 894 (8th Cir. 2024). Detwiler, however, provides guidance that district courts, at least those in the Ninth Circuit, may evaluate not just the sincerity of the belief, but also whether the belief itself is religious in nature.

In Petersen, the Court of Appeals applied the undue-hardship standard from Groff, emphasizing that employers must rely on specific, evidence-based assessments rather than generalized concerns. This decision reinforces that undue hardship must reflect actual operational, health, or financial risks – not hypothetical ones. Employers must make deliberate and detailed arguments, backed up with real and thorough evidence in making an undue hardship claim.

Together, these cases represent a heightened burden on employees to articulate a true religious basis for their objection and employers to present concrete evidence when asserting undue hardship. As more employees and employers navigate religious accommodation requests, these decisions offer meaningful guidance on how courts may evaluate an employee’s right to religious accommodations with an employer’s duty to provide a safe workplace.

Kolin Tang is a Partner, Matthew P. Suzor is an Associate, and Cameron Smith is a Legal Intern at Miller Shah LLP. 

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