The Oscar-nominated screenwriters and book author Walter Kirn claimed the the 22nd Annual USC Libraries Scripter Award for the hit film.
The Scripters recognise the author and writers of a produced literary work-to-film adaptation.
Reitman and Turner have already won a string of awards and are favourites to land gold at the Oscars next month (Mar10).
Also honoured at the Scripters was Eric Roth, the writer behind adaptations like Forrest Gump.
He was presented with a Scripter Literary Achievement Award.
The honours were handed out at a gala ceremony in Los Angeles on Saturday (07Feb10).