Diane A. Thompson

Of Counsel

Los Angeles

(213) 892-7939

(213) 892-7999

Diane focuses her practice on providing advice and counsel on matters pertaining to executive compensation and employee benefits. Her clients include public and private companies, as well as tax-exempt organizations, and she regularly works with board of directors compensation committees and company executives in finance, human resources, legal, and accounting.

She assists clients with the design and operation of cash bonus plans, incentive plans, and equity compensation programs. Diane also advises on executive compensation compliance and proxy disclosure, transaction due diligence and change of control payments, post-merger integration, qualified and non-qualified savings and retirement plans, deferred compensation, fiduciary duty, liability claims, vendor contract review, and helping clients select new benefits and compensation vendors. In addition, she consults with companies on human resources risk management, employment agreements, separation agreements, and payroll issues. Her practice includes assisting employers with IRS and DOL audits.

Diane served as a court-appointed receiver for the U.S. District Court in a fraud and violations of securities law case involving an administrator of self-directed 401(k) plans and IRAs. The company serviced account balances of $350 million, and more than 5,000 accounts invested in unique non-cash investments including real estate, LLC interests, foreign currency, and promissory notes. Over a four-year period, Diane acted as CEO, operating the business, liquidating assets, negotiating and settling legal claims, and procuring insurance settlements for the benefit of the victims. She led a team of more than 75 attorneys in assisting the government in successful civil and criminal claims against the perpetrator, completed the sale of the company, and the transfer of accounts to a successor custodian with a 92 percent recoupment.

In a previous role as corporate senior vice president of HR for AECOM (a NYSE professional services company with 45,000 employees in 130 countries), Diane led a team of more than 50 global HR employees and was responsible for executive compensation, incentives and stock compensation, benefits, human resources information, shared services, and global employee taxation issues.

Diane teaches part-time in the MBA-Tax graduate program at California State University Fullerton. Before joining Cozen O’Connor, she was a partner of a multinational accounting and professional services firm and a large, Philadelphia-based law firm.


An Election Agenda for Management if Biden Becomes President [Alert]

November 02, 2020

Jeff Pasek, Diane Thompson, Michael Corgan, and Anne Greene discuss the significant changes affecting a host of executive employment issues that could be implemented by a Biden administration.

Exec Employment Considerations Under A Biden White House [Law360]

October 30, 2020

Jeff Pasek, Diane Thompson, Anne Green, and Michael Corgan wrote an article about what a Joe Biden administration would look like for companies.

Executive Compensation Considerations Amid the COVID-19 Pandemic

September 09, 2020

Katayun Jaffari, Diane Thompson, and Anne Greene co-authored an article published in The Legal Intelligencer that examines the considerations companies must bear in mind when addressing executive compensation amid the COVID-19 pandemic.

Events & Seminars

Past Events

Startup Essentials Program

March 05, 2021 - Webinar


  • Loyola Law School, Los Angeles, J.D., 1987
  • California State University, M.A., 1980
  • California State University, B.A., 1977

Awards & Honors

The Legal 500 US, Labor and Employment - Employee benefits, executive compensation, and retirement plans - design, 2019

  • California
  • U.S. Tax Court

American Bar Association, Employee Benefits Committee

California Bar Association

Western Pension Benefits Association