Since 2009, Barnes & Thornburg has opened offices in Boston, Dallas, Detroit, Los Angeles, New York, Raleigh, San Diego,[4] Salt Lake, Atlanta, Minneapolis, Columbus.

[6][page needed] In April 2019, a ground-breaking ceremony took place for the firm's new office building in South Bend, Indiana.

[10] The firm remained in the 1st Source Bank Center until summer 2021,[11] when the South Bend branch relocated to their aforementioned current office at 201 S. Main Street.

[12] On June 4, 2021, Barnes & Thornburg announced that the partner who had signed onto the lawsuit had avoided internal authorization procedures and was no longer with the firm, and that it would be withdrawing as counsel on the suit.

[15] By expanding through mergers, they have acquired practice groups from other firms in the fields of labor and employment, intellectual property, and estate planning.