Hagan, 69, has said he was one of three gunmen who shot Malcolm X as he began a speech at Harlem's Audubon Ballroom on Feb. 21, 1965. But Hagan has said the two men convicted with him were not involved.
They maintained their innocence and were paroled in the 1980s. No one else has ever been charged.
The assassins gunned down Malcolm X out of anger at his split with the leadership of the Nation of Islam, the black Muslim movement for which he had once served as chief spokesman, said Hagan, who was then known as Talmadge X Hayer.
He has repeatedly expressed regret for his role in the assassination, which he described in a 2008 court filing as the deed of a young man who "acted out of rage on impulse and loyalty" to religious leaders.
"I've had a lot of time, a heck of a lot of time, to think about it," Hagan told a parole board last month, according to a transcript of the interview.
"I understand a lot better the dynamics of movements and what can happen inside movements, and conflicts that can come up, but I have deep regrets about my participation in that," said Hagan, adding that he had earned a master's degree in sociology since his conviction.
The board granted Hagan's parole request on his 17th try. He was initially scheduled for release Wednesday, but the date was moved up because his paperwork was completed, Foglia said.
Hagan declined to comment Tuesday afternoon.
"I really haven't had any time to gather my thoughts on anything," he said.
The Malcolm X & Dr. Betty Shabazz Memorial and Educational Center, an organization founded by the civil rights leader's late widow, hasn't taken a position on Hagan's parole, board chairman Zead Ramadan said.
"We just don't think it's ours to decide the fate of this man. We allowed the laws of this nation to develop that," Ramadan said.
But another group, the Malcolm X Commemoration Committee, decried Hagan's parole at a press conference earlier this month. The organization holds essay contests and other events in his memory.
The Manhattan District Attorney's office, which prosecuted Hagan and his co-defendants, had no immediate comment on his release.
Under his work-release arrangement, Hagan also spent five days a week working in settings that included a homeless shelter; he spent those nights at his Brooklyn home with his family. He told the parole board he hopes to become a substance abuse counselor.