Mark W. Zimmerman


Location: Chicago, IL

Phone: 312.606.7481


Mark W. Zimmerman is a shareholder with Clausen Miller P.C. who concentrates his practice in the area of insurance coverage litigation and other commercial disputes.

Mark represents insurance companies throughout the United States in wide array of complex insurance coverage matters, including environmental, asbestos, silica, toxic tort, advertising injury and reinsurance claims. In addition to the litigation and trial of insurance claims in various state, federal and bankruptcy court forums, Mark also has extensive experience in the mediation of large scale, multi-party coverage disputes. Mark often serves on insurer steering committees in the coverage matters he is involved with, and regularly deals with emerging and “first impression” coverage issues, including most recently the impact of corporate spin-offs on rights to coverage, and insurer standing to contest reorganization plans in asbestos and environmental bankruptcy matters.
In addition to his insurance coverage practice, Mark also has significant experience in general commercial and bankruptcy matters, including negotiating and drafting employment and other commercial contracts, litigating financial institution, U.C.C. and consumer fraud disputes and representing creditor and third-party interests in bankruptcy reorganization matters.

After graduating from Southern Illinois University in 1983 with a B.S. in Criminal Justice, Mark worked in law enforcement for eight years before becoming an attorney. Mark received his J.D. with honors from DePaul University School of law in 1993, where he was a member of the Board of Editors of the DePaul Law Review. After graduating from law school, Mark interned at the London, England law firm of Wilde Sapte, where he trained in and practiced British insurance and reinsurance law.

Mark is licensed to practice in the State of Illinois, the United States District Court for the Northern District of Illinois and the United States Court of Appeals for the Seventh and Tenth Circuits. Mark has also been admitted pro hac vice in numerous state and federal jurisdictions throughout the United States.

Mark is a member of the Illinois State and Chicago Bar Association, and serves on the CBA’s insurance law subcommittee.


  • J.D. DePaul University College of Law, 1993
  • B.S. Criminal Justice Southern Illinois University, 1983

Bar Admissions

  • Illinois

Court Admissions

  • U.S. District Court, Northern District of Illinois
  • U.S. District Court, Central District of Illinois
  • U.S. District Court, Eastern District of Wisconsin
  • U.S. District Court, Northern District of Indiana
  • U.S. District Court, Southern District of Indiana
  • U.S. Court of Appeals, Seventh Circuit
  • U.S. Court of Appeals, Tenth Circuit


  • Chicago Bar Association
  • Illinois State Bar Association
  • Defense Research Institute


  • Martindale Hubbell AV® rating
  • Leading Lawyers, 2020
  • Chicago

    Illinois 60603

    10 South LaSalle Street

    Chicago, Illinois 60603

    T: 312.855.1010 TF: 800.826.3505 F: 312.606.7777 Office Managing Partner: Dennis D. Fitzpatrick

  • New York

    New York 10005

    28 Liberty Street 39th Floor

    New York, New York 10005

    T: 212.805.3900 TF: 800.826.3505 F: 212.805.3939 Office Managing Partner: Tyler Lory

  • Mission Viejo

    California 92691

    27285 Las Ramblas

    Suite 200

    Mission Viejo, California 92691

    T: 949.260.3100 TF: 800.826.3505 F: 949.260.3190 Office Managing Partner: Ian R. Feldman

  • Florham Park

    New Jersey 07932

    100 Campus Drive

    Florham Park, New Jersey 07932

    T: 973.410.4130 TF: 800.826.3505 F: 973.410.4169 Office Managing Partner: Carl M. Perri

  • Michigan City

    Indiana 46360

    200 Commerce Square

    Michigan City, Indiana 46360

    T: 219.262.6106 TF: 800.826.3505 F: 312.606.7777 Office Managing Partners: Paige M. Neel, Kimbley A. Kearney

  • Appleton

    Wisconsin 54914

    4650 W. Spencer Street

    Appleton, Wisconsin 54914

    T: 920.560.4658 TF: 800.826.3505 F: 920.968.4650 Office Managing Partner: Patrick L. Breen

  • Stamford

    Connecticut 06902

    68 Southfield Avenue

    2 Stamford Landing Suite 100

    Stamford, Connecticut 06902

    T: 203.921.0303 TF: 800.826.3505 F: 212.805.3939 Office Managing Partner: Matthew J. Van Dusen

  • Tampa

    Florida 33609

    4830 West Kennedy Boulevard, One Urban Center

    Suite 600

    Tampa, Florida 33609

    T: 813.509.2578 TF: 800.826.3505 F: 312.606.7777 Office Managing Partner: Dennis D. Fitzpatrick

  • San Francisco

    California 94111

    100 Pine Street

    Suite 1250

    San Francisco, California 94111

    T: 415.745.3598 TF: 800.826.3505 F: 949.260.3190 Office Managing Partner: Ian R. Feldman