In 1987, Maguire was the artist on the re-launch of Justice League written by Keith Giffen and J. M. DeMatteis. The two writers and Maguire reunited in 2003 for the Formerly Known as the Justice League miniseries and its 2005 sequel, "I Can't Believe It's Not the Justice League" published in JLA Classified. Maguire's collaborations with Giffen and DeMatteis also include Defenders and Metal Men back-ups in the latest volume of Doom Patrol.
Maguire has frequently collaborated with writer Fabian Nicieza on series such as Adventures of Captain America, X-Men, andBatman Confidential. In 2007, he was the subject of Modern Masters #10 from TwoMorrows Publishing.
Maguire and George Pérez are alternating as artist of a revival of the Worlds' Finest series, which is written by Paul Levitz.