Fitch, Even, Tabin & Flannery

Fitch, Even, Tabin & Flannery LLP, commonly known as Fitch Even, is an intellectual property boutique headquartered in Chicago, Illinois. The firm maintains additional offices in Washington D.C., San Diego, and San Luis Obispo, California. Founded in 1859, Fitch Even is recognized as Chicago's oldest continuously operating law firm, with a focused practice in intellectual property and technology-related law. The firm is acknowledged in the 2026 edition of Chambers USA as a leading intellectual property firm in Illinois (Band 4) and was included in Vault's 2026-27 "Top 150 Under 150" list for firms with 150 or fewer attorneys. Chambers USA 2026 reports the firm has 42 lawyers.

The firm's IP litigation practice spans a wide array of technology areas and disputes, including patent, trade secret, trademark, copyright, unfair competition, and related commercial matters. Fitch Even handles technically demanding disputes across various industry sectors, such as Artificial Intelligence, Biotechnology + Pharmaceuticals, Computer Software + Hardware, Electronics, Mechanical Engineering + Manufacturing, and Medical Devices + Diagnostics. Historically, the firm served as counsel in the landmark patent case Arrhythmia Research Technology, Inc. v. Corazonix Corp., which addressed the patentability of software-based mathematical methods. While the firm states it represents both plaintiffs and defendants, its recent tracked appearances predominantly feature plaintiff-side representation.

Fitch Even has a notable and active Patent Trial and Appeal Board (PTAB) practice. The firm has represented clients in over 150 America Invents Act (AIA) trial proceedings since 2012. Recognized for its success, Fitch Even was identified as a top firm for patent owners in inter partes review (IPR) proceedings and has been ranked among the top 10 firms for preventing the institution of trial on behalf of patent owners. The firm's expertise in PTAB trial practice is also highlighted by Chambers USA.

Key partners in the firm's IP litigation practice include Mark S. Raskin and Donald E. Stout, both of whom have appeared as counsel in tracked patent litigation cases. Allen E. Hoover serves as the firm's Managing Partner and has significant experience as lead counsel in patent lawsuits. Calista Mitchell is also recognized by Chambers as a notable practitioner in the intellectual property field.