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.


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





Illinois Super Lawyers, 2019-2020

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 Discusses the False Claims Act in "Conversion on False Claims Act Expansion - Does it Make Sense?" with Tax Notes StateAugust 17, 2020

    In this discussion of the policy considerations of expanding state False Claims Act to taxes, Nikki E. Dobay and Stephanie T. Do interviewed four state and local tax experts who have experience with the ramifications of state false claims acts: Marilyn A. Wethekam, Helen Hecht, uniformity counsel and Brian Hamer, counsel to the Multistate Tax Commission and David Pope, partner…

  • Marilyn Wethekam Discusses How Old Tax Language Should be Amended for Modern TechnologyAugust 12, 2019

    State and local governments are trying to apply older tax laws to modern technologies such as streaming services. This one-size-fits-all ideology of the decades-old regulations leaves the law on shaky ground. Marilyn Wethekam discussed how shoehorning old tax laws to modern business services can be a setback at the Multistate Tax Commission's annual meeting in Boise, Idaho. "Ordinances and statutes…

  • Marilyn Wethekam Receives IPT's 2019 Distinguished Service AwardJune 28, 2019

    This award is presented to one or more individuals who have made outstanding contributions to the Institute over an extended period of time. Examples of the activities for which this award has been previously given include sustained and substantial contributions to one of the Institute's designations or educational programs. Learn more about the Institute for Professionals in Taxation here. …

  • Marilyn Wethekam Provides Insight On How States Are Responding To South Dakota v. WayfairJanuary 21, 2019

    An article published by Checkpoint discusses how states are responding to the South Dakota v. Wayfair  decision. Less than six months after the U.S. Supreme Court overturned the physical presence rule for sales and use tax nexus with its ruling in South Dakota v. Wayfair, the vast majority of states have enacted or announced economic nexus policies, and the trend…

  • Marilyn Wethekam Provides Insight on the Streamlined Sales and Use Tax AgreementOctober 30, 2018

    An article published by State Tax Notes discusses how the Alabama remote sales tax law could be the model for other states on taxing remote sellers. Alabama's Simplified Sellers Use Tax Remittance Act created a dual system under which local jurisdictions maintain control over the sales taxes of local businesses but not over remote sellers. State and Local Tax attorney,…


  • 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...

  • John Marshall Law School, LL.M.
  • Chicago-Kent College of Law, Illinois Institute of Technology, J.D.
  • Loyola University, B.A. in Political Science
  • Illinois
  • Texas
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Chicago IL 60661

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