He is best known for starring as Ricky Underwood on the ABC Family teen drama series The Secret Life of the American Teenager from 2008 to 2013.

After deciding to return to Los Angeles, Kagasoff landed the lead role in a local theater production of Suburbia, a play that the eponymous 1996 film was based upon.

During one of his first auditions, he impressed producer Brenda Hampton so much that she hand-picked him to star as Ricky Underwood in the ABC Family series The Secret Life of the American Teenager.

[7] It was announced on February 24, 2013, that Kagasoff had been cast as Alex in the Fox pilot Delirium, based on the novel by Lauren Oliver.

In September 2014, Kagasoff joined the cast of the Red Band Society, a comedy-drama series on Fox for the 2014–15 American television season developed by Margaret Nagle.