Volchenkov, who had a phone hearing with league disciplinarian Brendan Shanahan on Thursday morning, hit Marchand with an elbow in the second period of Wednesday's 5-4 loss to the Bruins, a play that earned him a five-minute major and a game misconduct.
Marchand, who went down on the play and had to be helped off the ice, did not return to the game.
Volchenkov, who has been suspended before for elbowing Carolina's Zach Boychuk back in February 2011, will forfeit $91,891.88, per the rules of the collective bargaining agreement.
The 31-year-old Volchenkov will not be eligible to return until the last week of the regular season on April 21, when the Devils face the New York Rangers at Madison Square Garden.
In a video explaining the decision, Shanahan described the elbow to Marchand as "reckless" and said Volchenkov was "fully responsible for the outcome."
Following practice Thursday, Volchenkov sounded prepared to face a suspension. He admitted that the hit probably looked bad but said he did not intend to injure Marchand.
"I was not trying to hurt him," Volchenkov said, explaining that he was trying to play the puck after taking a hit.
Volchenkov expressed remorse for putting his team in a bad situation.
The Devils may be down two defensemen when they host the slumping Ottawa Senators on Friday night.
While Volchenkov will be serving the suspension, captain Bryce Salvador may be unavailable as well.
The veteran defenseman was hit on the wrist by a shot from Boston's Zdeno Chara during the second period and did not return to the game. Although the Devils said Thursday that Salvador's X-rays came back negative, his return is still unclear.
Salvador is considered day-to-day.