The 2011 NBA lockout was the fourth and most recent lockout in the history of the National Basketball Association (NBA). Team owners began the work stoppage upon expiration of the 2005 collective bargaining agreement (CBA). The 161-day lockout began on July 1, 2011 and ended on December 8, 2011. It delayed the start of the 2011–12 regular season from November to December, and it reduced the regular season from 82 to 66 games. The previous lockout in 1998–99 had shortened the season to 50 games. During the lockout, teams could not trade, sign, or contact players. Players additionally did not have access to NBA team facilities, trainers, or staff.