The president did not appear to sustain any injuries. Gasps from the crowd followed Biden's fall, which came as he handed out the last diploma, forcing him to come down on his hands and knees.
Biden, who was helped to his feet by Air Force officials and Secret Service personnel, appeared to trip on a black sandbag that was on the stage.
Biden, 80, the oldest president in U.S. history, seemed to be OK and continued to stand as the ceremony concluded a few minutes later.
"He's fine," Ben LaBolt, White House communications director, said in a tweet. "There was a sandbag on stage while he was shaking hands."
Biden joked about the incident as he returned Thursday evening to the White House. "I got sandbagged!" Biden, holding up his arms, shouted to reporters with a smile before taking a slight skip when asked if he's feeling good. Biden walked with no visible limp.
It's not the first time Biden has tumbled in the public spotlight.
Last summer, Biden fell when he tried to get off his bike at the end of a ride at Cape Henlopen State Park near his beach home in Delaware, but said he wasn't hurt. He has also tripped but collected himself while speeding up the stairs to board Air Force One.
After Biden was elected in 2020, but before his inauguration, Biden fractured his foot when he slipped and twisted his ankle while playing with one of his dogs, forcing him to wear a walking boot for several weeks.
The latest fall likely hands Republicans − who have repeatedly questioned Biden's fitness to be president − new material for future ads in the 2024 presidential election after they've already made Biden's bicycle spill a go-to clip.
"He actually fell down?" former President Donald Trump said Thursday during a campaign event in Iowa when asked about Biden. "Well I hope he wasn't hurt."
Trump went on to reference the criticism he received in 2020 for walking gingerly down a ramp during the graduation ceremony of the U.S. Military Academy at West Point. Trump, now 76, also appeared to have trouble bringing a glass of water to his mouth during his speech.
"You gotta be careful about that because you don't want that, even if you have to tip toe down a ramp," Trump said. "I suffered for that. They never covered my speech."
Reach Joey Garrison on Twitter @joeygarrison.
This article originally appeared on USA TODAY: President Biden falls handing out diplomas at Air Force Academy