Marianne K. Lizza-Irwin

Marianne K. Lizza-Irwin

Counsel vCard
303.623.9222 fax
1200 Seventeenth Street
Suite 3000
Denver, CO 80202

Marianne Lizza-Irwin is an accomplished attorney, litigator, and experienced mediator and ADR professional, who brings knowledge, focus, and creativity to resolving disputes. With nearly 30 years of experience as a trial attorney and counselor at law, Marianne's practice focuses on complex commercial, insurance, and business disputes, as well as injury, wrongful death, construction, employment, property, and HOA matters. She carries a vast amount of experience as trial counsel at both the state and federal level, and significant expertise in her roles as mediator and arbitrator.

Marianne has mediated hundreds of cases in a wide variety of complex legal issues, including matters involving injury, business dissolutions, insurance coverage, commercial, employment, family, and HOA matters. She has also arbitrated personal injury, HOA, insurance, and commercial cases as both arbitrator and advocate, and acts as a facilitator in business and employment matters, in addition to providing special master services.

A member of several prominent legal associations, including the Colorado, Denver, and Jefferson County Bar Associations, Marianne continues to work with various legal and judicial figures to improve options and access to courts for legal and mediation services.

Memberships & Affiliations

  • Colorado Bar Association, Immediate Past Chair, ADR Section, 2014-present
  • American Board of Trial Advocates, Member, 2016-present
  • American Bar Association, ADR Section, 2017-2019
  • National Academy of Distinguished Neutrals, Member, 2019-present
  • Faculty of Federal Advocates, Member, 2014-present
  • Colorado Judicial Institute, Section Member, ADR, 2015-2019
  • U.S. District Court, Roster of Private Mediators, 2014-present
  • Association of Attorney Mediators, Member, 2017-present
  • Mediation Association of Colorado, Professional Member, 2014-present; Board Member, 2015-present


  • Colorado DORA, Mediation in HOAs, 2018, 2019
  • Litigation v. Mediation (Panel), ADR Section CLE, 2018
  • Regis University, Business College, Denver, CO: ADR in Colorado, 2017
  • 19th ADR Annual Conference, Colorado Bar, Denver, CO: ADR In the Courts, 2017
  • Federal Center, Federal Executive Board, Denver, CO: Mediation Practice in Colorado, 2017

Other Info


J.D., University of Detroit Mercy School of Law, 1984
B.S., University of Michigan, 1981, Natural Resource Science

Bar Admissions

Colorado, 1985

Court Admissions

U.S. District Court, Colorado
U.S. Court of Appeals, Tenth Circuit