Mary Kay McCalla Martire - McDermott Will & Emery


Mary Kay McCalla Martire focuses her practice on state and local tax disputes. She helps clients with audits, tax-related litigation, letter rulings and settlement conferences. Mary Kay has experience resolving disputes involving income, sales and use, utility and telecommunications taxes, as well as premium and retaliatory tax.

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  • Won Appellate Court verdict affirming dismissal of qui tam claim for over $1 million in attorneys’ fees. State of Illinois ex. rel. Stephen B. Diamond P.C. v. SR/Ecom, Inc., 2018 IL App. (1st) 172612
  • Won bench trial verdict for taxpayer in qui tam suit alleging failure to collect and remit sales tax on shipping charges. State of Illinois ex. rel. Stephen B. Diamond, P.C. v. Treasury Wine Estates Americas Co., No. 14 L 7563 (Aug. 30, 2016)
  • Won two appellate court rulings affirming the dismissal of qui tam lawsuits (State ex rel. Beeler, Schad & Diamond, P.C. v. Burlington Coat Factory Warehouse corp., 369 Ill. App. 3d 567 (1st Dist. 2006); People ex rel. Schad Diamond & Sheddon, P.C. v. QVC, Inc., 2015 IL App (1st) 13299 (April 21, 2015)) and obtained circuit court orders dismissing several other qui tam cases

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  • Martindale-Hubbell, AV Preeminent
  • Illinois Super Lawyer 2005 to 2011
  • Women in Tax Leaders, International Tax Review 2017 – 2022


  • Chicago Bar Association, State and Local Tax Committee, past chair
  • Chicago Lawyers Committee for Civil Rights Under Law, Inc., board member, past chair
  • PING! (Provide Instruments for the Next Generation), board member
  • Oak Park River Forest Women Leaders in Philanthropy


University of Michigan Law School, JD, 1985
Michigan State University, BA, 1982


United States Supreme Court
US Court of Appeals for the Sixth Circuit
US Court of Appeals for the Seventh Circuit

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