Diane M. Soubly

Diane M. Soubly is Of Counsel based in Butzel Long’s Ann Arbor office practicing in the areas of ERISA and employee benefits litigation, labor and employment law and litigation, and appellate litigation.

Diane M. Soubly is one of a select few attorneys nationally who have been elected Fellows of both the College of Labor and Employment Lawyers and the American College of Employee Benefits Counsel. Included in Best Lawyers for many years, Diane is a member of the Michigan and Illinois bars, and she has been recognized as a Super Lawyer in both of her fields of concentration in both Illinois and Michigan. With over 30 years of experience in class action litigation, ERISA and employee benefits litigation and plan design, labor and employment law, employment litigation, and appellate litigation, she is also a member of the bar of the US Supreme Court and the First, Fifth, Sixth, Seventh, Eighth and Eleventh Federal Circuit Courts of Appeal. She is an adjunct professor of law at Chicago-Kent School of Law and has served as an adjunct professor of law at the University of Detroit/Mercy Law School.

As an ERISA litigator, Diane has successfully represented employers, fiduciaries, plans, and plan sponsors in all facets of ERISA litigation, including individual and ERISA class actions involving:

  • retiree benefits,
  • imprudent investments (including stock drop issues),
  • excessive fees,
  • pension miscalculations,
  • cash balance plan conversions,
  • violations of ERISA's anti-cutback rule,
  • violations of ERISA §510,
  • discriminatory plan design,
  • various fiduciary breaches,
  • delinquent contributions,
  • withdrawal liability,
  • and trustee disputes.

Diane has also designed welfare benefit plans, severance pay plans, and voluntary and involuntary reduction-in-force plans. She is a sought after speaker and presenter on the Affordable Care Act, both on its “nuts and bolts” and on potential litigation. A frequent contributor to the Benefits Law Journal, she was recently appointed to its Editorial Board. In 2007, she was invited onto the Board of Directors of the American Benefits Council and served from 2007-2010; and she also served from 2007-2014 on the Council’s Legal Affairs Committee evaluating requests for amicus briefs.

As a labor and employment law litigator, Diane has represented private, public and non-profit employers in all facets of labor and employment litigation and counseling, including:

  • individual and class claims under federal and state discrimination laws, involving various statuses such as age, gender, national origin, religion, sexual orientation, gender identity.
  • trade secret violations and violations of non-compete and non-disclosure covenants under state and federal law (including RICO and the Computer Fraud and Abuse Act)
  • individual and class claims under federal and state wage and hour laws, and
  • claims for wrongful discharge, breach of employment contract and related tort claims,
  • individual and class claims for public policy discharge, and
  • scientific misconduct claims.

She has served as an investigator in highly sensitive personnel investigations (including sexual harassment and financial misconduct investigations), and she has been tapped as a mediator and an arbitrator in private disputes and in cases for the Equal Employment Opportunity Commission. She also served on the Labor and Employment Advisory Board of the Michigan Institute for Continuing Legal Education for ten years.

As an appellate lawyer, Diane has joined cases at the post-trial level and has obtained successful reversals on appeal. She has also protected favorable results on appeal. She is a frequent author of amicus briefs for national associations (including the Chamber of Commerce for the United States, the American Benefits Council, the National Association of Manufacturers, the Equal Employment Advisory Committee, and the HR Policy Association). In the recent wave of same-sex marriage cases, she filed sixteen amicus briefs on behalf of 18 of the nation’s leading constitutional law scholars in five different federal circuits and in the US Supreme Court; and she is consulting on the issue of domestic partner benefits and religious liberty issues in the workplace in the wake of the Supreme Court decision in Obergefell v Hodges.


  • Wayne State University 1971, M.A.
  • Wayne State University 1981, Ph.D.
  • University of Michigan Law School 1980, J.D.
  • Wayne State University 1970, B.A.


Fellow, College of Labor and Employment Lawyers

Fellow, College of Employee Benefits Counsel

The Best Lawyers in America

Michigan Super Lawyers

Illinois Super Lawyers

DBusiness Top Lawyers in Metro Detroit


  • Illinois
  • Michigan
  • Supreme Court of the United States
  • United States Court of Appeals for the Eighth Circuit
  • United States Court of Appeals for the Eleventh Circuit
  • United States Court of Appeals for the Fifth Circuit
  • United States Court of Appeals for the First Circuit
  • United States Court of Appeals for the Seventh Circuit
  • United States Court of Appeals for the Sixth Circuit
  • United States District Court for the Eastern District of Michigan
  • United States District Court for the Northern District of Illinois
  • United States District Court for the Western District of Michigan
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