The shooting guard led Washington in scoring last season with a career-high 17.4 points per game, more than doubling the 8.6 he averaged in the 2009-10 season.
His NBA career average is 10.9 points since being drafted in the first round by the Wizards in 2007.
Young's new contract was announced Monday, a day before Washington's second and last exhibition game, at the Philadelphia 76ers. In the Wizards' preseason opener, they had all sorts of problems on offense, making only 33 percent of their shots in a 103-78 loss to Philadelphia.
Washington opens the regular season Dec. 26 at home against the New Jersey Nets.