As workers throughout the U.S. rally against COVID-19 vaccine mandates, the federal agency charged with preventing workplace discrimination has updated its guidance on how employers should navigate religious-based requests for exemptions.

The Equal Employment Opportunity Commission reiterated on Monday that federal law requires employers to consider requests for religious accommodation — but that it does not have to grant those requests if doing so would present an undue hardship. The EEOC also clarified that employers aren't required to accommodate workers' "social, political, or economic views, or personal preferences."

The guidance comes ahead of a highly anticipated White House mandate expected to increase the number of worker requests for vaccination exceptions, either for religion or disability-based reasons. That directive is expected to require larger employers to mandate either COVID-19 vaccines or weekly testing for workers.

But the EEOC's guidance may do little to sort the legal boundaries for religious accommodation requests being tested in courtrooms across the country. These cases can be complex because employers have a right to probe whether a worker's stated religious belief actually conflicts with vaccination.

“That’s essentially the $64,000 question,” says Blank Rome's Gus Sandstrom, a labor and employment lawyer. “That’s where all the complication lies.”

Title VII protects religious-based discrimination

U.S. workers hoping to qualify for a religious exemption must show they have a sincere religious belief that conflicts with getting vaccinated against COVID-19. Sandstrom explains that employers generally steer clear of challenging the worker's sincerity because it's so challenging to prove, yet often delve into the connection between the religious belief and its purported conflict with the employer’s policy.

Workers have a right to a religious exemption under Title VII of the Civil Right Act, Sandstrom explains. Aside from a narrow set of employers who aren't engaged in interstate commerce, he says, the law covers nearly all U.S. employers and therefore nearly all U.S. workers. Even without the federal law, he said, a parallel state law would almost certainly require religious accommodation.

“Every employer should assume it applies to them,” Sandstrom says.

The Act obligates employers to make certain accommodations, such as prayer breaks or a schedule change to attend mass, to allow workers to do their jobs while keeping their religious practices intact. Under federal law, workers with sincerely held religious beliefs may work while unvaccinated so long as the accommodation doesn't burden the employer, LaKeisha Caton, a labor and employment attorney with Pryor Cashman, told Yahoo Finance.