 Carlson began his career as a National League umpire in , and has worked in both Major Leagues since .Carlson had previously worked in the Pioneer, Midwest, Florida State, Southern, International, and Arizona Fall leagues before reaching the MLB.Carlson has umpired the Division Series (2005, 2007, 2011, 2012, 2015), League Championship Series (2013, 2014, 2017, 2018, 2019) and World Series (2015).