Justin Krieger serves as the Managing Partner of the firm's Denver office. He is a first chair inter partes review (IPR) and post-grant review (PGR) litigator with a tremendously successful track record for challenging third party patents as well as defending against patent challenges brought before the Patent Trial & Appeal Board (PTAB). He also serves as an adjunct Professor of Law at the University of Denver Sturm College of Law where he teaches a course on PTAB studies. As a registered patent attorney, Mr. Krieger also focuses on client counseling, district court litigation, and patent prosecution. His technical focus includes chemistry, chemical engineering, biotechnology, medical devices, metallurgy, nanotechnology, mechanical engineering and consumer products. He has significant experience managing large domestic and international patent portfolios in these industries.

Mr. Krieger lectures and publishes frequently on various intellectual property topics, including the America Invents Act, the “on sale” bar to patentability, IPR and PGR proceedings, best practices in drafting patent applications and the Defend Trade Secrets Act of 2016.

Mr. Krieger was recommended by Legal 500 US in 2018, 2020 and 2021 for Patent Prosecution. He was named a top patent practitioner in 2018, 2019, 2020 and 2021 by IAM Patent 1000 – The World's Leading Patent Practitioners.

While attending law school, Mr. Krieger was a member of the Florida Law Review.


Mr. Krieger supervises a post-grant patent practice team that has consistently obtained favorable results for the firm’s clients. He has served as lead counsel in well over 20 IPR and PGR proceedings, representing clients both as petitioner and patent owner. Mr. Krieger has repeatedly beaten the odds: representing Patent Owners, he successfully achieved denial of institution in 8 IPRs, and won 5 IPRs after trial. All five cases going to trial resulted in the validation of all instituted claims—a result achieved in fewer than 5% of IPR proceedings. Representing client TerraLithium LLC, in 2020-2021, Mr. Krieger achieved complete victories in 7 IPRs, with institution denied or all patent claims affirmed after trial for all 7 different patents.

Representing Petitioners, Mr. Krieger has been equally successful: In 2017, Mr. Krieger successfully represented Petitioner in two IPRs, resulting in the Patent Owner requesting adverse judgment. In 2018, Mr. Krieger successfully took three IPRs to trial on behalf of Petitioner. In 2019, he achieved another win as IPR petitioner, resulting in an early grant of a client’s motion to terminate the proceeding on terms highly favorable for the client.

Mr. Krieger also actively prepares non-infringement and validity opinions including comprehensive freedom-to-operate (FTO) analyses in the chemical, polymer, medical device, and mechanical arts from both due diligence and litigation perspectives. Mr. Krieger also has been actively involved in numerous patent litigation matters and has participated in all phases of discovery, claim construction (Markman hearings), trial, and appeals. He is also experienced in Section 337 investigations before the U.S. International Trade Commission (ITC).

Mr. Krieger leads a patent prosecution team for clients in the fields of industrial chemistry and chemical engineering, pharmaceuticals, agrochemicals, medical devices and analytical instruments.


University of Florida College of Law J.D. (1999)

College of William and Mary B.S. (1995) Chemistry


Colorado (2018)

District of Columbia (2002)

New York (2000)

Court Admissions

U.S. Court of Appeals for the Federal Circuit

U.S. District Court for the District of Columbia

U.S. District Court for the Eastern District of Virginia

U.S. Patent and Trademark Office

U.S. Supreme Court

Professional & Community Activities

University of Denver Sturm College of Law, Adjunct Professor of Law, PTAB Practice

American Bar Association

Federal Circuit Bar Association

PTAB Bar Association

PTAB and TTAB Committee (Federal Circuit Bar Association)

American Intellectual Property Law Association

Intellectual Property Owners Association

American Chemical Society (ACS)

ACS Division of Chemical Education, Board of Trustees (2020-2022)

ACS Committee on Patents and Related Matters (2020-2022)

ITC Trial Lawyers Association


Latest Thinking

View more Insights
Insights Center
If you would like to receive related insights and information from Kilpatrick Townsend, please provide your contact details by filling out the form and clicking “Agree.” If you would like to access the PDF only, please click “Download Only.”