Ramona Shelburne of ESPN.com reported the sides agreed to a four-year, $72 million contract on July 1.
Noah confirmed his decision to sign with the Knicks with the following photo on his Instagram account:
Noah, 31, appeared in just 29 games for the Bulls this past season, averaging 4.3 points, 8.8 rebounds, 3.8 assists and one block per game. His season ended in January when he underwent surgery to repair his dislocated left shoulder.
Noah, in his prime, was one of the game's most dominant rebounding, defensive and passing big men. He was a force for the Bulls down low and was a fixture on Tom Thibodeau's best teams. He's a two-time All-Star, a three-time All-Defensive Team selection, the 2013-14 NBA Defensive Player of the Year and a 2013-14 All-NBA first team selection.
Injuries and age have reduced his impact the past two years, however.
Still, the Bulls reportedly wanted to re-sign Noah. Executive vice president John Paxson said Noah "represents a lot of things we believe in" this offseason, per K.C. Johnson of the Chicago Tribune.
Per Johnson, however, Noah didn't like his role with the team last season when he was healthy—he started just two games under new head coach Fred Hoiberg. He also clashed with Jimmy Butler, who wanted to take on a greater leadership role on the team.
Those factors likely played the key role in Noah's decision to leave Chicago and sign with the Knicks. Indeed, Noah never fit in Hoiberg's system, as his lack of a jump shot and offensive game made him a liability.
Noah, if he can stay healthy, remains a solid defensive player and a strong presence at the rim. He'll bring leadership and intensity to New York, and he remains a good passing big despite his diminishing offensive impact.
Noah is no longer one of the game's top centers, but he's still a valuable piece.
In New York, Noah will step into the starting center role, giving the Knicks a fascinating frontcourt that includes Kristaps Porzingis and Carmelo Anthony. Noah will provide a much-needed influx of defending and rebounding, and his reunion with Derrick Rose ensures that the Knicks won't be short on veteran leadership.
The signing is another indication that the Knicks won't be building a younger roster aimed at the future around Porzingis. This move, along with the trade for Rose, is a sign the team is trying to win right now. If Rose and Noah can stay healthy, the Knicks have the makings of a playoff roster.