The new unit merges IM2, the direct-response media operation of Initiative, with DraftWorldwide, a full-service direct-response shop.
Billings are estimated at $400 million.
Interpublic's move follows on the heels of similar media consolidations at Bcom3 Group's Starcom MediaVest Group, which recently consolidated its direct services as Halogen, and at Zenith Media, which launched Zenith Direct this year.
ID Media will be led by Chairman-CEO Lynn Fantom, who was formerly president and CEO of K2 Digital and previously had been president of DraftWorldwide's New York office.
Gaye Sussman, head of media services for DraftWorldwide New York, will serve as president of ID Media, overseeing U.S. operations.
Clients will include American Express, Verizon and Johnson & Johnson, among others.