He is best known for his roles as Paul Young in the ABC comedy-drama Desperate Housewives (2004–2011) and as Herman "Duck" Phillips in the AMC period drama Mad Men (2007–2015).

Moses played supporting roles in a number of movies, including Gettysburg (1993), Deep Impact (1998), One Man's Hero (1999), Big Momma's House 2 (2006), Swing Vote (2008), Cesar Chavez (2014) and Bombshell (2019).

He played Woodbury Kane in the 1997 miniseries Rough Riders and also guest-starred on Touched by an Angel, Star Trek: Voyager, ER, The West Wing, NYPD Blue, Drop Dead Diva, CSI: Crime Scene Investigation, Law & Order: Special Victims Unit, Scandal and Grey's Anatomy.

[2] In 2007, Moses joined the cast of AMC period drama series Mad Men playing a recurring role as Herman "Duck" Phillips.

He played the recurring roles of Secretary of Housing and Urban Development, and later President Jeffrey Michener in the TNT series The Last Ship from 2015 to 2018, and in the Telemundo/Netflix La Reina del Sur.