Daniel ZeilbergerDanielZeilberger
Partner, Intellectual Property
Daniel Zeilberger is a partner in the Litigation Department of Paul Hastings and is based in the firm’s Washington, D.C. office.
Daniel's practice focuses on intellectual property matters, including patent office proceedings, district court litigation and appeals to the Court of Appeals for the Federal Circuit. Daniel has substantial experience leading teams in all aspects of IP litigation. His cases involve a wide range of technical areas, including internet-related technologies, mobile devices, semiconductor devices, telecommunications, business methods, medical devices and pharmaceuticals. Prior to entering private practice, Daniel served as a patent examiner at the USPTO, where he gained valuable experience with USPTO standards and procedures.
Georgetown University Law Center, J.D., 2013
Johns Hopkins University, B.S.E.E., 2007
Avery Dennison RFID Co. v. EVRYTHNG Ltd. (S.D.N.Y. & D. Mass.). Represented EVRYTHNG in litigation involving Internet of Things (IoT) technology.
Chevron Oronite Company v. Infineum USA L.P. (PTAB). Represented Chevron Oronite in IPR challenging patent directed to lubricating oil composition. All claims found unpatentable by PTAB and decision affirmed on appeal.
- Rising Star
Managing Intellectual Property''s IP Stars (2025)
- Paul Hastings Client Service Excellence Award
Various case summaries, Federal Circuit Bar Association Circuit Case Digest, Co-author
SEPTEMBER 14, 2026
“Federal Circuit Clarifies the Scope of IPR Estoppel,” Lexology, Co-author
MAY 9, 2025
“USPTO Rescinds Memorandum Addressing Discretionary Denial Procedures,” Lexology, Co-author
MARCH 3, 2025
“Federal Circuit Rules PTAB APJs Violate Appointments Clause,” Lexology, Co-author
NOVEMBER 1, 2019
“A Divided Supreme Court Upholds Inter Partes Review’s Constitutionality but Constrains the Patent Office''s Authority,” Lexology, Co-author
APRIL 25, 2018
"The APA in PTAB Proceedings: Notice and an Opportunity to Be Heard,” Landslide® magazine, Volume 10, Issue 3, Co-author January/
February 2018
“PTAB Section 315(b) Time-Bar Determinations Reviewable at the Federal Circuit,” Lexology, Co-author
JANUARY 10, 2018
“No Article III Standing Requirement for Appellees in Appeals from IPR Proceedings,” Lexology, Co-author
AUGUST 8, 2017
“Prosecution History Disclaimer Extends to IPR Proceedings,” Lexology, Co-author
MAY 16, 2017
“PTAB Upholds Acorda’s Ampyra® Patents, Rejecting Challenges Based on Inventors’ Own Work,” Lexology, Co-author
MARCH 15, 2017
“Give Your PTAB Record the Nutrition It Needs to Fight for You: Techniques for Discovery and Success Before the PTAB and the Federal Circuit,” AIPLA Mid-Winter Institute, Co-author
FEBRUARY 3, 2017
“Use of PTAB Decisions in District Court Litigation,” IP Watchdog, Co-author
SEPTEMBER 19, 2016
“Five Years In: The AIA’s Effects on Patent Litigation,” Bloomberg Law, Co-author
SEPTEMBER 8, 2016
“Some Federal Circuit Guidance on Procedural Safeguards for PTAB,” Law360, Co-author
JUNE 30, 2016
“Federal Circuit Provides Guidance on the APA’s Procedural Safeguards for PTAB Proceedings,” Lexology, Co-author
JUNE 16, 2016
“PTAB Provides Guidance on AIA Estoppel Provisions,” Managing Intellectual Property, Co-author
OCTOBER 28, 2015
“Quick Fixes Implemented, New Rules on the Way for PTAB Trial Practice,” Lexology, Co-author
APRIL 1, 2015
Treasurer
PTAB Bar Association (2025
Board of Directors
PTAB Bar Association (2021
- “Effective Use of an Expert in a PTAB Trial,” PTAB Bar Association Annual Conference, SpeakerMARCH 10, 2023
- “Appeals from the PTAB,” PTAB Bar Association Annual Conference, ModeratorSEPTEMBER 23, 2021