Marilyn A. Wethekam Partner
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Marilyn A. Wethekam
"I’ve seen state tax issues from both sides of the table—and understand the solutions these complex issues require."

Marilyn is a partner at HMB and a member of the firm’s State and Local Tax (SALT) Group. She advises Fortune 500 companies on the resolution of complex multi-state and multi-national tax issues.

Marilyn assists publicly traded multinational and multistate clients work through sophisticated multistate income, franchise and transaction tax matters. Clients benefit from her wealth of experience in SALT, 18 years of which were spent in-house at Mobil Oil and Montgomery Ward & Co.

On behalf of clients facing intense scrutiny, Marilyn formulates multistate audit strategies— and has represented them before taxing authorities in more than 35 states. She has helped companies adopt new organizational structures that have reduced their tax burdens and improved their financial positions.

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A Leader in the SALT World

Marilyn is one of the most recognized forces in the SALT community. She’s the recipient of the Council of State Taxation’s Paul Frankel Excellence in State Taxation Award, Bloomberg BNA’s Excellence in State Taxation Award, Tax Analyst’s Leading Female Tax Counsel and is noted as one of Crain’s Chicago’s Notable Women Lawyers.

Clients rely on Marilyn for innovative and practical solutions driven by her in-house experience and profound understanding of the SALT world.


  • University of Illinois, Chicago School of Law, LL.M.
  • Chicago-Kent College of Law, Illinois Institute of Technology, J.D.
  • Loyola University, B.A. in Political Science





Illinois Super Lawyers, 2019-2021

Chicago’s Notable Women Lawyers, Crain’s Custom Media, 2018

Franklin C. Latcham Award, Bloomberg BNA, 2012

Paul Frankel Excellence in State Taxation Award

Bloomberg BNA, Frank Latcham Award for Distinguished Service in State and Local Tax Law, 2012

Outstanding Women in Tax by Tax Notes, 2016

Professional Memberships

  • American Bar Association, Member
  • Bloomberg BNA State Tax Advisory Board, Member
  • Chicago Tax Club, Member
  • Council on State Taxation, Past Chair
  • Georgetown University Institute on State and Local Taxation, Advisory Board Member
  • Illinois State Bar Association, Member
  • Paul J. Hartman State Tax Forum, Advisory Board Member
  • Texas Bar Association, Member
  • State Tax Notes, Advisory Board Member




  • Marilyn A. Wethekam Featured in State Tax Notes Article, "Marilyn Wethekam: A SALT Trailblazer Who's Paid the Cost"May 10, 2021

    Read the full article by State Tax Notes written by Doug Sheppard here. In one of the most famous scenes from The Blues Brothers, Sister Mary Stigmata doles out rapid-fire corporal punishment with a ruler on Jake and Elwood Blues, then breaks it on Elwood's head before Jake crashes down an adjacent flight of stairs in the ensuing chaos. “Get out! And don’t come back until you’ve redeemed yourselves,”…

  • Marilyn A. Wethekam Discusses the Tax Legacy of Former Illinois House Speaker Michael Madigan with Law360January 22, 2021

    Read the full article here (subscription required). Former Illinois House Speaker Michael Madigan was recently voted out of his leadership post, leaving a complex tax legacy to his nearly four-decade reign that included sales tax restructuring and failures to create the progressive income tax code he envisioned. Madigan, a Democrat from Chicago, ceded the gavel on Jan. 13 after House members elected…

  • Marilyn A. Wethekam Discusses Illinois' Adoption of Rule with Criticized Online Sales Tax Sourcing with Law360January 19, 2021

    In an article by Law360, Marilyn A. Wethekam discusses the Illinois Department of Revenue's decision to carry out a law that critics say could impose a discriminatory tax sourcing regime for online sales that favors certain in-state sellers. The rule carries out a widely criticized 2019 law requiring remote sellers and marketplace facilitators without a physical presence in Illinois to employ destination sourcing for…

  • Marilyn A. Wethekam Discusses the Year Ahead in SALT Law with State Tax NotesJanuary 18, 2021

    Read the full article by State Tax Notes here. In the article "Forging Ahead in 2021" by State Tax Notes on December 21, 2020, Marilyn A. Wethekam goes over what the year ahead will look like. “Should old 2020 be forgot, and never brought to mind? Should old 2020 be forgot, and auld lang syne?”[51] The Robert Burns lyrics pose…

  • Marilyn A. Wethekam Discusses Voluntary Disclosure Programs with Tax Notes Today StateNovember 30, 2020

    Download the full article by State Tax Notes here. In the article "Sales, Use Tax Voluntary Disclosure Agreements Increased" by State Tax Notes and first discussed at the NESTOA conference on November 13, 2020, Marilyn A. Wethekam goes over the use of Voluntary Disclosure programs. There's been an uptick in voluntary disclosure agreements (VDAs) because of the Supreme Court's 2018…


  • In the Matter of Product of Conagra Foods Ingredient Co., New Mexico Administrative Hearing Office, Dkt. No. 17-39, September 15, 2017October 2, 2017

    The New Mexico Office of Administrative Hearings granted Conagra Foods? Motion for Summary Judgment concluding the interest earned on notes was properly characterized as non-business income.

  • The Cubs Won the World Series and Illinois Finally Has a Budget!July 7, 2017

    Today marks the first time in over two years that Illinois will be operating under a budget. This is a result after the House voted to override Governor Rauner?s veto of Senate Bill 9. The House garnered the necessary votes to end the two year stalemate full of political puffery and sparring. Some of the relevant changes that Illinois? taxpayers should be aware of are noted below. All changes are effective July 1, 2017, unless otherwise noted.

  • Factor Presence Nexus- Be Careful What You Wish For!September 14, 2016

    A recent Chief Counsel?s Ruling issued by the California Franchise Tax Board illustrates the issues and potential opportunities that arise as a result of adopting a factor presence nexus standard.

  • Tax Deficiencies and Automatic Penalties: Challenging by Reasonable Cause?December 12, 2014

    Increasingly, taxpayers are seeing the imposition of penalties on deficiency assessments. In fact in a number of situations the imposition of the penalty is automatic upon the issuance of the assessment. The penalties, which may range from 20% to 25% of the liability, are imposed for late payment or underpayment of taxes. Such penalties are generally imposed without taking into consideration the fact there is a lack of guidance or legal authority with respect to the substantive issue which gave rise to the tax underpayment...

  • University of Illinois, Chicago School of Law, LL.M.
  • Chicago-Kent College of Law, Illinois Institute of Technology, J.D.
  • Loyola University, B.A. in Political Science
  • Illinois
  • Texas
500 West Madison Suite 3700
Chicago IL 60661

Phone: 312-606-3200 Fax: 312-606-3232
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