Cousins umpired in the World Series in 1988, 1999 and 2005. He also officiated in the All-Star Game in 1987, 1998 and 2008, and was behind the plate for the 2008 game at Yankee Stadium, which lasted a record 4 hours 50 minutes before ending in the 15th inning. He worked in seven League Championship Series (1985, 1989, 1995, 2003, 2006, 2008, 2010), and in five Division Series (1997, 1999, 2002, 2005, 2007). Cousins was promoted to crew chief for the 2008 season. He was also crew chief during the semi-finals and finals of the 2009 World Baseball Classic, and served as the home plate umpire in the latter game.