Richardson will be eligible to return to the Jets on Monday, Oct. 5, after the Jets' Week 4 game against the Miami Dolphins.
"I apologize for letting down my family, teammates, this organization and the fans. However, words aren't enough. This is something that can only be addressed by how I handle myself from this point on," Richardson said in a statement.
"I don't want this to take away from what the team is trying to accomplish. While I won't be there at the start of the regular season, I will do whatever I can to support my teammates until I'm able to return to the field."
Richardson also took to Twitter to address his suspension.
I vow to you, this will not happen again. My team will continue to push forward without me to start the season.— Sheldon Richardson (@Godforshort) July 2, 2015
Richardson is eligible to practice and play with the Jets during the preseason, as his suspension begins with Week 1 of the regular season.
"This is disappointing for Sheldon and the team. We're going to support Sheldon and welcome him back upon his return. We will keep moving forward with our preparations for the upcoming season," Jets coach Todd Bowles said in the statement.
Richardson, 24, had eight sacks, 66 tackles and a forced fumble last season, his second in the NFL. He was the NFL Defensive Rookie of the Year in 2013, finishing with 3.5 sacks, 78 tackles and a forced fumble after he was selected 13th overall in the first round by the Jets earlier that year.
The Jets drafted defensive end Leonard Williams with the fourth overall pick in the 2015 draft, adding the rookie to what the team hopes will be a fearsome defensive line anchored by star defensive end Muhammad Wilkerson and also featuring Richardson and nose tackle Damon Harrison.