Yost's most high-profile work was his appearance in Mighty Morphin Power Rangers: The Movie (1995),[2] which took in over $60 million at the box office.

When asked about the change in a 2010 interview, Yost was evasive about how he'd personally felt about this but said he understood why the production team did it; he stated that Haim Saban was interested in the cast turnover of Super Sentai and believes that this was part of it.

According to Yost, he was often called a "faggot", and the producers frequently questioned other cast members in private about his sexuality.

Yost left late in the fourth season after a week of contemplation and thoughts of suicide instead of continuing work another six months into the second film.

He stated that the co-workers involved with writing, filming, and producing the show considered him "not worthy" to be where he was and that he "could not be a superhero" because of his homosexuality.

[7] After Yost left the show, he attempted to change his sexual orientation with conversion therapy for two years.

In 2016, Yost became co-owner of Affirmative Clothing along with Harlingen, Texas entrepreneurs Mason and Cris Andrade.

Named after one of Billy's catch phrases, Affirmative has apparel with designs mostly inspired by Power Rangers, which Yost and the Andrade brothers first sold on conventions they attended.

[20] In September 2022, it was announced that Yost was returning to the Power Rangers franchise for a 30th-anniversary special, accompanied by original Black Ranger actor Walter Emanuel Jones as well as former co-stars Steve Cardenas, Johnny Yong Bosch, Karan Ashley, and Catherine Sutherland.