Biggio, 42, retired last season after playing his entire 20-year career with Houston. The seven-time All-Star is the franchise's career leader in hits, games, runs scored and at-bats. Last season, he became the 27th player in history to reach 3,000 hits and was honored with a trophy before Friday night's game against Philadelphia for the top moment of the 2007 season, as voted by fans online.
Biggio will become the ninth Astro to have his number retired by the team.
"It's something that, it'll be forever," Biggio said. "Even though you play the game for a long time, that doesn't necessarily mean you get your number retired. The way you play the game and the things you're able to do, that's going to happen. It's one of the greatest feelings you ever have as a player."
Biggio's number will hang next to Jeff Bagwell's No. 5, above the video scoreboard in right field. Biggio and Bagwell played 15 seasons together in Houston and anchored six teams that made the playoffs. Bagwell, whose number was retired last August, is the franchise's career leader in home runs and RBIs.
"We played together so long, we knew each other so well," Biggio said. "I couldn't think of a better person to have your name sitting next to. I couldn't have had a better teammate."
Biggio, who won four Gold Gloves, said he hasn't gotten the itch to play again as he's watched the Astros this season. He's working as a special assistant to Astros general manager Ed Wade and he was recently hired by a local high school to coach his son's baseball team.
"I've been so busy with my family and my kids and so many other things, I really haven't had any time to slow down," he said.
Owner Drayton McLane announced the number retirement ceremony on the field before the Astros played Philadelphia. Biggio got a standing ovation as he waved to the adoring fans one more time.
"I miss it a little bit, when you get on the field and hear the ovations and how the fans cheer for you," he said. "I miss that part of it."
The first 10,000 fans received miniature replicas of Biggio's famously nicked and dirt-stained batting helmet. Biggio said the original helmet is at home, hanging from the antler of a deer mounted on the wall.