Parker has appeared in about a dozen feature films, also including Juno (as an unnamed high school chemistry lab partner) and Little Miss Sunshine (as an unnamed teen-aged boy). On television, Parker played the supporting role of Harold, a young medical intern, on the 14th season of ER. He played a pizza delivery impostor in a late-2008 television advertisement for DiGiorno frozen pizza.
Parker was a contestant on The Price Is Right on his birthday in January 2010. However, he did not win the game and ended up with only 55 cents when spinning the Big Wheel, which was not enough to make it into the "Showcase Showdown". The show was broadcast on CBS on March 2, 2010.
On October 26, 2015, Lost the Musical: We Have to Go Back (co-written by Parker with Steven Brandon, premiered at the Lillian Theater in Hollywood. A musical comedy based on the long-running TV show Lost, the spoof musical offered each audience a choice of three different endings, which The Hollywood Reporter characterized as ""'70s cartoon," "'80s sci-fi movie" or "'90s sitcom.""
Two years later, Parker and Brandon again collaborated to write and produce another musical spoofing a popular TV series, Game of Thrones the Rock Musical: An Unauthorized Parody. The show premiered at the Macha Theatre in West Hollywood,, and also performed in San Diego during 2017 Comic-Con before moving to the Jerry Orbach Theater Off Broadway in NYC.
