Biello has been the team's assistant coach in the North American Soccer League (NASL) since November 19, 2009, following a career that spanned 19 seasons as a professional player, 16 of which were with the Impact.
"I am very proud to follow the club to Major League Soccer," said Biello. "This is an historic moment for the club and I am pleased to have the opportunity to help build the team for 2012. After being a part of the club's evolution starting in 1993, I consider myself lucky to be a part of this new chapter."
"Mauro Biello's commitment to this club has been monumental and he will be an incredible asset on and off the field as the Montreal Impact move into MLS," said Impact head coach Jesse Marsch. "I am delighted that he will remain a member of the coaching staff."