John J. D'AttomoJohn J. D'Attomo

John J. D'Attomo

Of Counsel




John is a highly-skilled and accomplished litigator concentrating his practice on business and health care litigation matters. He has extensive experience litigating a broad range of business disputes in the trial and appellate courts throughout the country. John regularly represents individuals and businesses in disputes involving claims of breach of contract, unfair competition, trade secret misappropriation, antitrust violations and breach of fiduciary duty. His practice also includes counseling clients with respect to the enforceability of non-compete agreements and, where necessary, litigating these matters in court proceedings. John has been involved in numerous litigated mortgage foreclosure actions as well as "workout" transactions arising from mortgage defaults by borrowers. John also has substantial experience in bankruptcy litigation matters having served as litigation counsel to a Chapter 11 Trustee in more than 30 adversary proceedings.

In the health care litigation arena, John has prosecuted and defended antitrust claims between competing health plans, between hospitals and physicians, and between hospital systems. He has also litigated matters involving the suspension or revocation of physician staff privileges, as well as disputes arising from physician peer review proceedings.  John was lead trial counsel in the only-known case involving the suspension of physician clinical privileges tried to a jury in Illinois.  Additionally, John was one of the lead trial attorneys representing a nonprofit hospital before the Illinois Department of Revenue following the unprecedented revocation of its tax-exempt status.

John's prior experience includes more than 13 years practicing with a large law firm, including five years as a partner. Prior to entering private practice, John served for two years as a judicial law clerk for a federal district court judge.

Published Works:

Hospital Must Report Voluntary Surrender of Privileges to the NPDB Notwithstanding Potential Invalidity of Underlying Action, BNA Health Law Reporter, 24 HLR 1444 (Nov. 5, 2015).

Litigating The Suspension of Physician Clinical Privileges: The Intersection Of The Illinois Medical Studies Act And The Rule of "At Issue" Waiver, ISBA Health Care Law Section Newsletter (June 2012)

Court Reverses $33 Million Damages Award In Favor of Suspended Cardiologist On Grounds Of Peer Review Immunity, Drinker Biddle Health Law Beat (Spring 2009)

Negligent Credentialing: Illinois The Latest State To Recognize The Tort, Drinker Biddle Health Law Beat (Spring 2009)

Wireless Communications Provider Defeats Vendor's Claim for $1 Million Arising From Blanket Purchase Order, Drinker Biddle Client Alert (Feb. 2009)

The "Buyer's Option" Contract in Illinois, 96 Ill. B.J. 418 (Aug. 2008)

Recovering Damages For Wrongfully Issued Injunctions in Illinois, 92 Ill. B.J. 34 (Jan. 2004)

Health Insurer Defeats Attempted Monopolization Claim, BlueCross BlueShield Association Legal Affairs Bulletin (Feb. 2002)

South Dakota Case Will Be Significant Precedent For Hospital Governing Boards To Take Economic Factors Into Consideration When Granting Medical Staff Privileges, Gardner Carton & Douglas Client Memorandum (Jan. 2001)

Practice Areas


  • John Marshall Law School, Chicago, JD, 1993, Cum Laude, Law Review: John Marshall Law Review, 1992 - 1993
  • Loyola University Chicago, BS, Criminal Justice, 1990, Magna Cum Laude