President Biden's mandate that about 3.5 million federal employees get vaccinated against COVID-19 was blocked by the 5th U.S. Circuit Court of Appeals on Thursday.
The president originally issued the executive order in September 2021, requiring workers to be vaccinated unless they have a medical or religious exemption.
On Thursday, 10 of the 5th Circuit's 16 judges reversed that decision, ruling that there is no constitutional basis for requiring federal employees to be vaccinated.
The White House did not immediately respond to a request for comment on Thursday evening.
A similar vaccine mandate for private sector businesses with at least 100 employees was blocked by the Supreme Court in January 2022. Health care workers at institutions that receive Medicare and Medicaid funding are still required to be vaccinated unless they have medical or religious exemptions.