After the 1984 Bell System Divestiture, Indiana Bell became a part of Ameritech, one of the 7 original Regional Bell Operating Companies. The Indiana Bell name continued to be used until January 1993, when they dropped all of their individual Bell Operating Company names in favor of using their corporate name, Ameritech, for marketing purposes, resulting in Indiana Bell Telephone Company, Inc. d/b/a Ameritech Indiana. In 2002, 3 years after Ameritech was acquired by SBC Communications, SBC rebranded all of its companies "SBC" for use as a national brand. Indiana Bell then was renamed Indiana Bell Telephone Company, Inc. d/b/a SBC Indiana. After AT&T Corp. was acquired by SBC Communications, SBC renamed itself AT&T, resulting in Indiana Bell being renamed Indiana Bell Telephone Company, Inc. d/b/a AT&T Indiana.
After being held by AT&T (pre-1984), Ameritech, and SBC, as of 2005, they are now part of the "new" AT&T.