Currently he is a writer and supervising producer for The Late Show with Stephen Colbert, where he has made several on-camera appearances. In 2003, Dinello co-authored the novel Wigfield with Amy Sedaris and Colbert, which they promoted by creating a traveling play. Most recently, Dinello has made guest appearances on Colbert"s show The Colbert Report as Tad, the building manager.
The character is often berated by Colbert, who forces him to do dangerous things.
Dinello has made at least five appearances on The Colbert Report, including a tumbling act with Colbert and their Strangers co-star Sedaris in July 2006. They resumed their insinuations of a sexual relationship from Strangers with Candy.
Dinello was also a writer, producer, and director for the Strangers with Candy film, which was released in July 2006. In January 2009, Participant Media announced that it would produce Dinello"s next film, Mr.
Burnout (about a burned out teacher seeking to rekindle his love of teaching).
He was one of the main cast in the show Exit 57, also starring Sedaris and Colbert. He also appeared as Mr. Rooney in the film Be Kind Rewind, alongside Jack Black and Mos Defense
With Sedaris, Dinello co-authored Simple Times: Crafts for Poor People, published in 2010.
He can be seen with Sedaris in the "Mummified Hand" episode of the Science Channel show Oddities.