The bank said Lewis will retire as a CEO and as a director, but stay on board to ensure a successor can be named.
Lewis is at the center of a controversy involving the bank and leading U.S. bank regulators over the purchase of Merrill Lynch, which Bank of America purchased early this year.
Bank of America rescued Merrill Lynch as it was crumbling in the financial crisis last fall. Allegations after the fact, however, include a secret deal to allow Merrill Lynch employees to receive billions in bonus pay despite Merrill Lynch's losses and keeping facts from shareholders who voted to approve of the purchase.
Lewis has testified he understood federal regulators had threatened to remove Bank of America executives from their jobs if the deal was abandoned.
"Ken Lewis was a key architect in building a truly global financial franchise," said Walter Massey, Chairman of the Board of Directors said in a statement. "We are on a solid path to the future."