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Mark R. Davis

Mark R. Davis


“Most property tax lawyers focus on the economics of the property tax equation. But many legal issues regarding the classification and valuation of property come into play in many matters and often are more significant.”

Mark R. Davis

Mark R. Davis represents clients in Cook County and throughout the U.S., focusing on real estate tax issues and related litigation. Before joining the firm in 1989, Mark worked in the Chicago Office of the State’s Attorney of Cook County as Supervisor of the Tax Division, where he directed 12 attorneys, conducting all trial and appellate litigation on behalf of Cook County government related to real estate and personal property taxation

Appointed a Special Assistant State’s Attorney of Cook County in 1997 to study and recommend structural changes in the State’s Attorney’s Tax Division, Mark argued a case before the Illinois Supreme Court to uphold the reformed judicial tax appeal provisions of the Illinois Property Tax Code. The Court voted to uphold the reforms. Over the last two decades, however, restrictive interpretations of the reform law by the Cook County taxing authorities made it largely ineffective as a taxpayer remedy against violations of federal and state constitutional equality principles. In 2020, Mark was lead counsel in persuading the U.S. Court of Appeals for the Seventh Circuit to uphold federal jurisdiction in a case challenging these restrictive interpretations of the reform law on constitutional grounds.


Mark focuses his practice on property taxation matters for:

  • National and regional real estate developers and institutional investors, and owners of industrial, retail, office and multi-family properties
  • Corporate real estate campuses
  • Small to mid-sized businesses

Practice areas:

  • Property tax assessment litigation in Illinois and other jurisdictions
  • Administrative appeals
  • Property tax exemption and enforcement

“We strive for complete coverage of the world of property tax problems and disputes. Clients often come to us with problems that they have been unable to resolve through ordinary tax appeal processes, often because of unusual legal issues.”


The Civic Federation: Chairman, Board of Directors, 2012–2014

Member of:

Chicago Bar Association and its Committee on Real Estate Taxation

The Civic Federation and its Executive Committee and Property Tax Committee

Illinois State Bar Association and its State & Local Tax Section Council

Illinois Chamber of Commerce, Tax Institute

Illinois Taxpayer’s Federation and its Property Tax Advisory Committee

Institute of Professionals in Taxation

International Association of Assessing Officers

Certified Illinois Assessing Officer (by the Illinois Property Assessment Institute)

bar admissions

Illinois Supreme Court, 1979

State Bar of Michigan, 2009

U.S. Court of Appeals for the Federal Circuit, 1998

U.S. Court of Appeals for the Seventh Circuit, 1981

U.S. District Court for the Northern District of Illinois, 1979

U.S. Supreme Court, 1999


DePaul University College of Law, J.D., 1979

University of New Mexico, B.A. with distinction; elected to Phi Beta Kappa, 1975

Government Service

Office of the State’s Attorney of Cook County, Illinois: 1979 – 1989

  • Supervisor, Tax Division
  • Assistant State’s Attorney

Office of the State’s Attorney of Cook County, Illinois: 1997

  • Special Assistant State’s Attorney