In November 2020, Squar Milner merged with Baker Tilly, the 12th largest CPA firm in The U.S. Before it was acquired, Squar Milner was one of the largest accounting and advisory firms in California. It was also the 40th-largest accounting firm in the U.S. by annual revenues, according to Accounting Today’s 2020 rankings. The firm had more than 650 professionals and over 80 partners who worked out of California offices in Los Angeles, San Diego, San Francisco, Encino, Silicon Valley, San Mateo, Woodland Hills, and Irvine; another location in the Cayman Islands provided financial services to alternative investment funds and hedge funds.

Although Squar Milner was best known as a Southern California firm, it provided accounting and financial services to clients in all 50 states and in 51 countries. Squar Milner was led by Managing Partner Steve Milner, who began his career as a Deloitte & Touche tax consultant, and later served as vice president and corporate controller for Birtcher Real Estate, one of the country’s largest developers and property managers. Milner now leads Baker Tilly's Western Region practice.