[4] Greenberger was hired to assist Len Wein and Marv Wolfman by the then DC Vice President/Executive Editor Dick Giordano.
The company was then organizing its output with the major comic book crossover Crisis on Infinite Earths and the guidebook Who's Who: The Definitive Directory of the DC Universe.
[5] Based on his work during this period, Greenberger was promoted to editor the following year, being assigned the titles Star Trek, Suicide Squad, and Doom Patrol.
After losing the 2009 election, he was appointed to represent Fairfield on the Greater Bridgeport Regional Planning Agency through June 2011.
Greenberger was hired to work under Joe Quesada, but was let go during a tumultuous reorganization overseen by Bill Jemas.