Don M. Millis

Don M. Millis is a seasoned tax attorney and Reinhart’s Tax Practice shareholder. He leads Wisconsin’s most extensive tax litigation practice and co-chairs the firm’s Government Relations Group. With extensive experience in property tax, sales and use tax, and income/franchise tax disputes, Don helps businesses navigate complex tax challenges while minimizing financial burdens. His strategic approach to litigation and negotiation has saved clients millions in state and local taxes.

Don earned his J.D. cum laude from the University of Wisconsin Law School. He also holds a B.A. in Journalism and Political Science from the University of Wisconsin-Madison. His legal and policy background equips him with the skills to handle intricate tax matters and advocate effectively for businesses.

Don represents various businesses, from national corporations to regional firms, in resolving tax disputes. His expertise includes property tax assessments, sales and use tax compliance and income/franchise tax litigation. As a former chair of the Wisconsin Tax Appeals Commission (1995-2004), he has deep knowledge of tax law and administrative proceedings.

In addition to representing clients before local and state tax authorities, Don has successfully handled tax disputes before the Wisconsin Tax Appeals Commission, circuit courts, the court of appeals, and the Wisconsin Supreme Court. He also provides strategic government relations and tax lobbying services, working directly on tax legislation and policy to help shape the tax laws that affect businesses across Wisconsin.

Don M. Millis’s straightforward advice and commitment to efficient dispute resolution make him a trusted advocate for businesses facing tax assessments and audits. His strategic litigation and negotiation skills enable companies to reduce tax liabilities and maintain compliance with evolving tax regulations. His leadership in government relations and tax policy further strengthens his ability to protect clients’ interests.

With a reputation for excellence in tax law and litigation, Don continues to be a vital resource for businesses seeking to navigate complex tax challenges while maintaining financial stability.

Law Office Affiliations

• Shareholder, Reinhart Boerner Van Deuren s.c.
• Member, Institute of Professionals in Taxation
• Member, Wisconsin State and Local Tax Club
• Member, International Association of Assessing Officers
• Member, State Bar of Wisconsin
• Member, Western District of Wisconsin Bar Association
• Member, Dane County Bar Association
• Chair, Wisconsin Elections Commission

Licensed State

• Wisconsin

Education

• University of Wisconsin Law School
  Juris Doctor (JD)
• University of Wisconsin-Madison
  Bachelor of Science (BA)

Awards & Badges