The Firm was founded on March 1, 1987, after the Firm in which Mr. Michael M. McCall was a partner dissolved. Mr. McCall had been with the prior firm since July 1977, and the predecessor Firm was Mr. McCall's only public accounting experience. The Firm's initial client base was 35 municipal utility districts purchased from the predecessor firm. In September of 1992, the Firm's name was changed to McCall & Company.

Debbie Gibson was originally hired by the predecessor firm in September, 1985. When that firm dissolved, Ms. Gibson joined the McCall firm. Effective January 1, 1998, the Firm was incorporated under the name McCall, Gibson & Company, PLLC, and Debbie Gibson became a shareholder.

Effective January 1, 2006, Christopher (Chris) J. Swedlund and Noel W. Barfoot became shareholders in the Firm. Chris first joined the Firm in 1994 after graduation from Abilene Christian University. Noel first worked for the Firm from 1996 until 1998, after graduation from the University of Houston. In 1998, he moved back to his native Beaumont/Orange area, working as an auditor for a CPA firm in Beaumont. He recently moved back to Houston and the Firm.