Armstrong and Phillips would end up working on a variety of other films together including Old School (2003), Starsky & Hutch (2004), School for Scoundrels (2006), and The Hangover: Part II (2011). Outside of his partnership with Phillips, Armstrong was also responsible for uncredited rewrites of Elf and Bad Santa. In 2007, he co-wrote the Farrelly Brothers' film, The Heartbreak Kid. The following year, Semi-Pro, which was Armstrong's first solo-written film, was released.