In 2004, he appeared as a guest in an episode of Cold Case as Lionel Royce, the leader of the "Black Liberation Front" section in Philadelphia in 1969.
In 2008 he joined the main cast of Crash, in which he played Anthony Adams, a street pilot, until the end of the series in 2009. His portrayal of Anthony Adams, a chauffeur and aspiring hip-hop Artist, led to the iTunes release of Head Up, a song that is performed by Sims in the third episode of the series.
In 2010, he appeared as a guest on Criminal Minds, where he played Tony Torrell, the former landlord and victim of serial killer Kaman Scott (Leonard Roberts).
In 2012, he played Michael Thomas, the brother-in-law of NCIS Director Leon Vance in the series NCIS.
In 2014, he joined the recurring cast of the second season of the series Masters of Sex where he played Robert Franklin, brother of Coral (Keke Palmer) and a civil rights Activist.
In 2016, Sims joined the cast of I'm Dying Up Here, a dark comedy produced by Jim Carrey. He is also currently shooting the seasons 4 and 5 of The Last Ship.
