President Biden ordered COVID-19 vaccines for almost all federal workers on Thursday, Sept. 9, but the U.S. Postal Service’s 600,000 letter carriers and administrative staff will be exempt.

Biden signed two executive orders on Thursday, Sept. 9: one requiring vaccination for most federal employees with limited medical and religious exemptions, and the other requiring federal contractors to vaccinate their workforces as well, New York Post reported.

Biden also announced a new Labor Department regulation requiring employees at private companies with 100 or more employees to get vaccinated or submit to weekly testing.

According to a senior administration official, businesses that ignore compliance with the new vaccine and testing regulations could face fines of up to $14,000 per violation. Biden said the new requirements would help “protect vaccinated workers from unvaccinated coworkers.”

White House officials told the Washington Post that the U.S. Postal Service employees are exempt from the Biden administration’s new coronavirus vaccine mandates for federal workers.

“We strongly encourage them to comply with these standards,” White House officials stated.

However, nearly four hours after that understanding was reported, the White House clarified that, like large-company workers, postal workers would have the choice of being vaccinated or getting tested once a week.

“USPS is not included in the executive order requiring vaccination of Federal employees. USPS has a separate statutory scheme and is traditionally independent of federal personnel actions like this,” a Biden administration official said.

He added: “That said, USPS is strongly encouraged to comply. Also, [the Labor Department’s Occupational Safety and Health Administration] will cover USPS through the [emergency temporary standards], meaning that postal workers will be subject to the vaccination or testing policy announced today.”

One of the Postal Service’s most influential unions, the American Postal Workers Union, criticized the administration’s efforts to mandate federal workers to be vaccinated in July and urged that postal leadership engage collectively on the issue.

“While the APWU leadership continues to encourage postal workers to voluntarily get vaccinated, it is not the role of the federal government to mandate vaccinations for the employees we represent,” the union said in a statement.