The Associated Press reported this, citing the organization Global Reach, which had campaigned for Gilman's release.
He will be taken to a military hospital in Texas, where he will undergo medical and psychological examinations and receive treatment.
Gilman's sister, Lexi Hudson, said that her brother's release was made possible thanks to President Donald Trump and Massachusetts Senator Ed Markey.
She also said that Russian authorities had treated her brother brutally.
"The Russians treated my brother so badly. They hurt him for no reason, other than that he was both an American and a Marine," Hudson said.
Trump said on his social media platform Truth Social that Gilman was expected to arrive Tuesday evening at Andrews Air Force Base near Washington.
The White House chief said that he had spoken with Russian President Vladimir Putin before the American was released.
"After my discussions with President Vladimir Putin, Russia has agreed to release him, very much on a Humanitarian Basis. We appreciate this decision, and the fact that Russia asked for no one in return — No exchange took place," Trump said.
He also said that he had personally spoken with Gilman.
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"I just spoke with him, and he had one request — A GREAT cheeseburger when he lands. I will take care of that!" the U.S. president wrote.
Trump also added that Gilman had been reunited with his mother, Nancy, who is flying back with him from Russia.
Gilman was detained by Russian authorities in 2022. He was initially sentenced to three and a half years in prison for assaulting a police officer after he was removed from a train for disorderly conduct. He was later repeatedly convicted of assaulting prison staff, and his total prison sentence was increased to 10 years.
Before his release, the 32-year-old American was being held in the psychiatric department of a civilian hospital. According to his lawyer, Gilman's condition had been deteriorating.
Photo: The White House