The Pentagon had previously ordered all 1.3 million active-duty service members to be vaccinated against the coronavirus. To date, over 93% have received at least one dose.
But Fox News obtained a memo signed by Deputy Secretary of Defense Kathleen Hicks, which directs civilian employees to also become vaccinated.
"All DoD civilian employees must be fully vaccinated by November 22, 2021, subject to exemptions as required by law," Hicks wrote, noting that employees are considered fully vaccinated two weeks after completing the second dose of a two-dose COVID-19 vaccine, like Pfizer-BioNtech or Moderna, or two weeks after receiving a single dose of a one-dose COVID-19 vaccine, like Johnson & Johnson.
"New DoD civilian employees must be fully vaccinated by their entry on duty (start) date or November 22, 2021, whichever is later," Hicks wrote.
Hicks cited the executive order President Biden signed last month, directing all executive branch agencies to implement a COVID-19 vaccine requirement for federal employees to "ensure the health and safety of the Federal workforce and members of the public with whom they interact."
In the memo, Hicks said those who are not currently fully vaccinated must meet several deadlines.
For those receiving their first dose of Moderna, individuals have until Oct. 11 to do so, with those receiving Pfizer having until Oct. 18. Hicks said individuals must receive their second doses of either Moderna or Pfizer by Nov. 8.
Civilian employees have until Nov. 8 to receive their only dose of the Johnson & Johnson vaccine.
Hicks said that employees "must be prepared to provide a copy of their COVID-19 vaccine record in order to meet forthcoming procedures for DoD COVID-19 vaccine verification."
Hicks added that additional guidance, including procedures for processing vaccination exemption requests, will be published.
"Vaccinating DoD civilian employees against COVID-19 will save lives and allow for the defense of our Nation," Hicks wrote. "Thank you for your focus on this critical mission."
Despite some concern over vaccine mandates, the Justice Department Office of Legal Counsel determined over the summer that federal law does not prohibit public agencies and private businesses from requiring COVID-19 vaccines that are under emergency use authorization (EUA).
The opinion notes that some have questioned whether such entities can lawfully impose such requirements.
In the opinion, the DOJ Office of Legal Counsel says the law concerning emergency- use authorizations "does not prohibit public or private entities from imposing vaccine requirements, even when the only vaccines available are those authorized under EUAs."
The Pfizer-BioNTech COVID-19 vaccine was fully approved by the Food and Drug Administration in August.