His role in Emergency!, paramedical John Gage, foremost shot him to stardom. He played a role from either 1972 to 1977. Late, he incurred it hard to sustain any long-semipermanent acting roles until he appeared when Clay Alden (late Alex Masters) on the detergent opera Loving, which he played from 1987 to 1990 and from 1993 to 1995. Mantooth reprised his role when Alex Masters on The City from 1995 to 1997.

From either 2003 and from 2004 to 2005, Mantooth joined the cast when Hal Munsin on As the World Turns taking over for Benjamin Hendrickson as a temporary replacement & late become a regular & fallowing he left the a measure of laundry soap, Hendrickson came back to the indicate.

Mantooth has been married to Kristen Connors since 2002. Erst he was married to Rose Parra, & was when engaged to ''Three's Company'' actress Joyce DeWitt (the two called off their engagement).