The league's disciplinary committee ruled Friday both that Schallibaum and the Impact were fined an undisclosed amount for violating a mass confrontation policy during their 5-0 victory over the Houston Dynamo on Aug. 24.
The Impact and Dynamo got into a skirmish in the 25th minute as Houstn's Adam Moffat and Montreal's Hernan Bernardello battled for a ball.
Schallibaum was not on the sidelines for the game, as he was serving the first of a two-game suspension for leaving the bench area to get into a shouting match in the team's previous game against D.C. United. He had also been fined $5,000 for "repeated misbehaviour."
The first-year coach watched the game from a private box at Saputo Stadium as assistant coach Mauro Biello took over at the bench. Schallibaum has been suspended four times in his first MLS season for a total of five games.
The league said the Impact and their coach were fined because it was a second violation this season. The Dynamo escaped a fine but can be sanctioned if it breaks the rule again.
The committe also fined Toronto FC forward Robert Earnshaw for making contact with head of D.C. United defender Daniel Woolard in the 90th minute of a 1-1 draw on Aug. 24.