Marc Guggenheim is a veteran writer for TVís The Practice, Law & Order, CSI: Miami, and most recently, Brothers & Sisters. He is also currently a writer for Marvel Comics. His brother is screenwriter Eric Guggenheim.
Hailing from Long Island New York, he worked in Boston as a lawyer and part-time writer for five years. After a romantic comedy script led to a few meetings he decided to make the move west to be a screen writer. He based the time of this move to coincide with the season that television companies hire new writers. The Practice was his first official job.
His writing experiences also include the comics Aquaman for DC, Wolverine and The Punisher for Marvel, and an undetermined amount of script work for the Rare Game Perfect Dark Zero. He also served as a supervising editor for Law and Order, Jack and Bobby, CSI: Miami,and In Justice. He even served as an intern at Marvel for a time in 1990 for editor Terry Kavanaugh (Excalibur, Namor, Marvel Comics Presents). He also managed to color an eight page Iceman/Human Torch story while there.
In November 2006, it was announced that Guggenheim would be assuming the writing duties for the Flash (comics). At the time, it was expected that Guggenheim would be writing the Flash for an indefinite period of time, but Guggenheim's story concluded with the death of "Bart Allen" (the 4th Flash), and that volume of Flash ended in June, 2007. It was then revealed that Guggenheim was brought onboard as writer to make way for the return of Wally West as the Flash, (and for Mark Waid to return to writing the Flash).
At the "San Diego Comic-Con" in 2007, it was announced that Guggenheim would be one of the rotating team of writers on "Amazing Spider-Man" starting in the Fall of 2007, (after the "One More Day" storyline in the "Spider-Man" books concluded). And, indeed, Amazing Spider-Man #546 has a story by Guggenheim.
Guggenheim is still involved in television script writing, and with Greg Berlanti, he is the co-writer of Eli Stone, a television pilot for ABC which started pre-production in 2006. Guggenheim was instrumental in the pilot's promotion of the theory that a mercury-based vaccine preservative causes autism. This theory is not supported by scientific evidence, but has contributed to decreased vaccination rates that endanger children. Guggenheim, who has two young children, said "I haven't vaccinated them as aggressively as I could."
He will be launching a new Marvel comicbook the Young X-Men in April 2008.