Washington — Defense Secretary Pete Hegseth announced Tuesday that the Department of Defense will no longer mandate U.S. service members to receive the flu shot each year.

In a video posted to X, Hegseth said troops will be free to choose whether to get vaccinated against the flu, and the shot will not be required by the Pentagon.

"The notion that a flu vaccine must be mandatory for every service member everywhere in every circumstance at all times is just overly broad and not rational," he said.

Hegseth said the decision to end the flu-vaccination mandate is part of the Trump administration's effort to "restore freedom and strength to our joint force."

"We're seizing this moment to discard any absurd, overreaching mandates that only weaken our war-fighting capabilities. In this case, this includes the universal flu vaccine and the mandate behind it," he said.

A memorandum signed by Hegseth on Monday states that "effective immediately, the annual influenza vaccine is voluntary for all Active and Reserve Component Service members" and civilians working for the Defense Department.

The shift comes after the Pentagon began moving away from its requirement that all service members — active duty and reservists — receive a seasonal flu shot. In a May 29, 2025, memo, Deputy Secretary of Defense Steve Feinberg wrote that the department would "conserve its resources by requiring seasonal flu vaccination for service members only when doing so most directly contributes to readiness."

The directive states that only reserve troops activated for at least 30 days would be required to receive flu shots, and the Pentagon would no longer pay reservists or members of the National Guard for their time spent getting the vaccine on their own.

The Navy and Marine Corps Force Health Protection Command, which develops and shapes public health for those services, states that seasonal flu vaccination "is the most effective control measure to reduce the risk of severe influenza and mission degradation, minimizing the risk to force." The organization warns that because the flu can spread quickly, outbreaks "may be widespread and can adversely impact Navy and Marine Corps force readiness and mission execution."

Under the Biden administration, the Pentagon also required the COVID-19 vaccine for all service members. Roughly 8,700 active duty and reserve troops voluntarily or involuntarily left the military after refusing to get vaccinated against the coronavirus, and the mandate was rescinded in 2023.

Soon after the start of President Trump's second term, he signed an executive order making reinstatement available to troops who were discharged for refusing the COVID shot. As of last August, less than two dozen service members had been reinstated, though hundreds had applied.

The military's first vaccination program dates back to 1777, when Gen. George Washington directed the inoculation of the Continental Army to protect against smallpox, according to a 2021 report from the Congressional Research Service. The Defense Department requires all military personnel to receive a number of vaccinations, including hepatitis B, polio, and measles, mumps and rubella, among others.

The flu vaccine was first mandated for troops in 1945, which led to the vaccination of 7 million people, according to a 2022 analysis of vaccine mandates in the military. That requirement was withdrawn in 1949, though the flu shot was mandated again in the early 1950s and remained that way until Hegseth's announcement, according to the article.