Moisés has made guest appearances on shows such as The Suite Life of Zack & Cody, Everybody Hates Chris and Wizards of Waverly Place. He had a recurring role as Rico on Hannah Montana, and became a series regular in the show's second season. In 2009, he played Andre in the Disney Channel Original Movie Dadnapped. As a regular on the Disney Channel, he participated on the first and second Disney Channel Games on the red team. He also participated in the third Disney Channel games on the Yellow Team (Comets).
He appeared in music videos for Pearl Jam, and the Jonas Brothers video for their song "SOS", and Parmalee, and the 2006 film Nacho Libre in a minor role. He participated in the Guadalajara Film Festival (2009) during the presentation of the movie The Perfect Game with Eva Longoria. Arias appeared on the ESPN family of networks as a roving 'sideline' reporter conducting interviews with fans and players at the 2009 Little League World Series. He appeared in Beethoven's Big Break in 2008. He appeared in Wizards of Waverly Place and played Max (Jake T. Austin)'s conscience.
During the summer of 2012, Arias filmed The Kings of Summer, which had its premiere on January 19, 2013, at the 2013 Sundance Film Festival to rave reviews.