Skip to content
umberg-zipser-llp
  • (949) 679-0052
  • [email protected]
  • ABOUT
    • Firm Overview
    • Selected Honors & Awards
    • Professional Activities & Community Involvement
    • Charitable Support
    • Careers
  • PRACTICE AREAS
    • Commercial Litigation
    • Intellectual Property
    • Lawyer Liability & Legal Ethics
    • Class Actions
    • Government & Regulatory
    • White Collar Investigations & Defense
  • PROFESSIONALS
    • Ryan S. Dean
    • Ethan Feng
    • Martin Fessenmaier, Ph.D.
    • Mark A. Finkelstein
    • Scott Garner
    • Amy Lesperance Han
    • Phillip Kaplan
    • Nasser Khateeb
    • Ellen Kim
    • Molly Magnuson
    • Priti Phukan, Ph.D.
    • Marcus S. Quintanilla
    • Carole Reagan
    • Todd Smith
    • Jeremy G. Suiter
    • Ryan T. Tran
    • Mei Tsang
    • Thomas Umberg
    • Chris Wang
    • Dean Zipser
  • NEWS
  • CONTACT
  • ABOUT
    • Firm Overview
    • Selected Honors & Awards
    • Professional Activities & Community Involvement
    • Charitable Support
    • Careers
  • PRACTICE AREAS
    • Commercial Litigation
    • Intellectual Property
    • Lawyer Liability & Legal Ethics
    • Class Actions
    • Government & Regulatory
    • White Collar Investigations & Defense
  • PROFESSIONALS
    • Ryan S. Dean
    • Ethan Feng
    • Martin Fessenmaier, Ph.D.
    • Mark A. Finkelstein
    • Scott Garner
    • Amy Lesperance Han
    • Phillip Kaplan
    • Nasser Khateeb
    • Ellen Kim
    • Molly Magnuson
    • Priti Phukan, Ph.D.
    • Marcus S. Quintanilla
    • Carole Reagan
    • Todd Smith
    • Jeremy G. Suiter
    • Ryan T. Tran
    • Mei Tsang
    • Thomas Umberg
    • Chris Wang
    • Dean Zipser
  • NEWS
  • CONTACT

Lawyer Liability & Legal Ethics

PRACTICE AREAS

Commercial Litigation

Intellectual Property

Lawyer Liability and Legal Ethics

Class Actions

Government & Regulatory

White Collar Investigations & Defense

We have extensive experience defending law firms and lawyers against claims by former clients and third parties, including claims of legal malpractice, breach of fiduciary duty, and securities fraud. We have represented lawyers accused of mishandling an array of underlying transactional and litigation matters, and have represented lawyers in connection with claimed ethical violations, including motions for disqualification. Our clients range from the largest international law firms, to small local firms, to individual lawyers.

In addition to defending claims, we also provide ethics counseling to law firms and lawyers. Our lawyers have served at the highest levels of state and local bar ethics committees, including as Chair of the State Bar’s Committee on Professional Responsibility and Conduct, Co-Vice Chair of the State Bar’s Rules Revision Commission, and Co-Chair of the Orange County Bar Association’s Professionalism and Ethics Committee. With that background and experience, our lawyers have been called upon to serve as expert witnesses on ethics and standard of care issues.

Umberg Zipser

1920 Main Street, Suite 750 Irvine CA 92614

Contact Us

If you are interested in retaining our services, or you want to learn more about Umberg/Zipser, we look forward to hearing from you.  Please note that merely sending us an email does not create an attorney-client relationship, and anything you send to us will not be confidential or privileged unless we have agreed to represent you. 

  • (949) 679-0052
  • 1920 Main Street, Suite 750, Irvine, CA 92614
  • [email protected]
  • www.uzllp.com

Umberg/Zipser is a premier business litigation and intellectual property boutique.  Drawing on decades of experience in some of the nation’s largest and most prestigious law firms, as well as national and state government service, Umberg/Zipser provides clients with unparalleled legal services. 

Linkedin Rss Envelope

Navigation

  • ABOUT
    • Firm Overview
    • Selected Honors & Awards
    • Professional Activities & Community Involvement
    • Charitable Support
    • Careers
  • PRACTICE AREAS
    • Commercial Litigation
    • Intellectual Property
    • Lawyer Liability & Legal Ethics
    • Class Actions
    • Government & Regulatory
    • White Collar Investigations & Defense
  • PROFESSIONALS
    • Ryan S. Dean
    • Ethan Feng
    • Martin Fessenmaier, Ph.D.
    • Mark A. Finkelstein
    • Scott Garner
    • Amy Lesperance Han
    • Phillip Kaplan
    • Nasser Khateeb
    • Ellen Kim
    • Molly Magnuson
    • Priti Phukan, Ph.D.
    • Marcus S. Quintanilla
    • Carole Reagan
    • Todd Smith
    • Jeremy G. Suiter
    • Ryan T. Tran
    • Mei Tsang
    • Thomas Umberg
    • Chris Wang
    • Dean Zipser
  • NEWS
  • CONTACT
  • ABOUT
    • Firm Overview
    • Selected Honors & Awards
    • Professional Activities & Community Involvement
    • Charitable Support
    • Careers
  • PRACTICE AREAS
    • Commercial Litigation
    • Intellectual Property
    • Lawyer Liability & Legal Ethics
    • Class Actions
    • Government & Regulatory
    • White Collar Investigations & Defense
  • PROFESSIONALS
    • Ryan S. Dean
    • Ethan Feng
    • Martin Fessenmaier, Ph.D.
    • Mark A. Finkelstein
    • Scott Garner
    • Amy Lesperance Han
    • Phillip Kaplan
    • Nasser Khateeb
    • Ellen Kim
    • Molly Magnuson
    • Priti Phukan, Ph.D.
    • Marcus S. Quintanilla
    • Carole Reagan
    • Todd Smith
    • Jeremy G. Suiter
    • Ryan T. Tran
    • Mei Tsang
    • Thomas Umberg
    • Chris Wang
    • Dean Zipser
  • NEWS
  • CONTACT

TRANSLATE

Subscribe

Contact Us

Copyright © 2026 - Umberg/Zipser | All rights reserved. Copyright & Legal Disclaimer
Made with ❤ by Excelsior Creative
Manage Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
  • Manage options
  • Manage services
  • Manage {vendor_count} vendors
  • Read more about these purposes
View preferences
  • {title}
  • {title}
  • {title}