Ruivivar's early appearances include the films Race the Sun (1996) and a minor character in Starship Troopers (1997).

In the show, Carlos was a Hawaiian-born Filipino-American who was abandoned by his family and spent his youth in various foster homes.

After Third Watch, Ruivivar remained in the drama genre, usually playing a police officer, detective or FBI agent in shows such as Traveler, Quantico, Numb3rs, Criminal Minds, CSI: Crime Scene Investigation (all 2007) and Lie to Me (2009).

In January 1998, he married actress Yvonne Jung, who would later appear in seasons 5 and 6 (2003–05) of Third Watch as FDNY EMS Paramedic Holly Levine.

They have 3 children; two sons, Kainoa and Kale, and a daughter, Levi, who is a member of the Philippines Women's Gymnastics national team.