California

Patent attorneys in California

California hosts 9,567 active patent practitioners registered with the USPTO Office of Enrollment and Discipline. Patent attorneys and patent agents can both prepare and file patent applications, but only patent attorneys can also offer legal advice on prosecution strategy, freedom-to-operate analyses, and infringement opinions in California. Practitioners are concentrated across 20 cities, with the largest clusters in the metros listed below. Notable firms with multiple registered practitioners in the state include Faegre Drinker Biddle & Reath LLP, Silicon Valley Patent Group, and Kilpatrick Townsend and Stockton.

Top cities in California

All practitioners in California

Thomas B Manuel

Reg. 56227

Patent attorney

Half Moon Bay, CA · 94019

650-833-9816

Daniel Huaizhou Mao

Reg. 51995

Patent agent

Faegre Drinker Biddle & Reath LLP

San Francisco, CA · 94111

415-591-7571

Edward S Mao

Reg. 40713

Patent attorney

Silicon Valley Patent Group

Santa Clara, CA · 95054

408-857-0559

Helen Z Mao

Reg. 61355

Patent agent

San Jose, CA · 95129

408-802-4098

Hsiang-Kuen Mao

Reg. 51996

Patent agent

Elk Grove, CA · 95758

916-686-0878

Stephen A Mao

Reg. 73418

Patent attorney

Kilpatrick Townsend and Stockton

Menlo Park, CA · 94025

650-326-2400

Yifan Mao

Reg. 60804

Patent attorney

Kilpatrick Townsend & Stockton LLP

Menlo Park, CA · 94025

650-324-6311

Andrew N Mar

Reg. 59698

Patent attorney

Procopio, Cory, Hargreaves & Savitch LLP

San Diego, CA · 92101

619-906-5624

Julie Y Mar-Spinola

Reg. 33533

Patent attorney

Finjan Holdings LLC

Redwood City, CA · 94063

650-526-8208

Nora A Marachelian

Reg. 68087

Patent attorney

Knobbe Martens Olson & Bear LLP

Irvine, CA · 92614

949-721-6316

Andre L Marais

Reg. 48095

Patent attorney

Schwegman, Lundberg & Woessner, P.A.

San Jose, CA · 95113

408-278-4040

Constantine Marantidis

Reg. 39759

Patent attorney

Christie, Parker & Hale, LLP

Glendale, CA · 91205

626-795-9900

Mark Joseph Marcelli

Reg. 36593

Patent attorney

Del Mar, CA · 92014

619-677-5747

Michael A. Marcelli

Reg. 56976

Patent attorney

Marcelli Law Office, A Professional Law Corporation

Simi Valley, CA · 93065

805-527-7875

Christopher S. Marchese

Reg. 37177

Patent attorney

Fish & Richardson, P.C.

San Diego, CA · 92130-2081

858-678-5070

Brian I Marcus

Reg. 34511

Patent attorney

Vierra Magen Marcus LLP

San Francisco, CA · 94105

415-489-4100

Lynn Marcus-Wyner

Reg. 34869

Patent attorney

Codexis, Inc.

Redwood City, CA · 94063

650-421-8208

Jonathan Mares· Ph.D.

Reg. 82781

Patent agent

Bozicevic, Field & Francis LLP

Redwood City, CA · 94065

650-833-7713

Moses Mares

Reg. 40716

Patent attorney

Paramount Pictures Corporation

Los Angeles, CA · 90038

323-956-8702

Catherine Cecilia Maresh

Reg. 35268

Patent attorney

San Francisco, CA · 94123

415-717-3655

Grant W Margulieux

Reg. 75021

Patent agent

Wilson Sonsini Goodrich & Rosati

San Diego, CA · 92130

858-350-2356

Jonathan A Marina

Reg. 69644

Patent attorney

Arcadia, CA · 91006

626-203-8090

Fabio E Marino

Reg. 43339

Patent attorney

Polsinelli LLP

Palo Alto, CA · 94304

650-461-7706

Alec M. Markarian

Reg. 84594

Patent agent

Kubota & Basol LLP

Los Angeles, CA · 90017

213-361-9304

Marina S Markarian

Reg. 77349

Patent agent

Milbank LLP

Los Angeles, CA · 90067

818-679-4566

David Markevitch

Reg. 64903

Patent attorney

Kaiser Gornick LLP

San Francisco, CA · 94105

415-857-7482

Samantha C . Markley

Reg. 70756

Patent attorney

Loza & Loza LLP

Upland, CA · 91786

877-406-5164

David A Markoff

Reg. 78375

Patent attorney

Kioxia America Inc

Irvine, CA · 92617

703-608-7294

Tereza Markova

Reg. 901044

Limited recognition

Thomas Jefferson School of Law

San Diego, CA · 92101

971-719-7472

Lindsey Nicole Marks

Reg. 902911

Limited recognition

University of California, Los Angeles School of Law

Los Angeles, CA · 90095-1476

203-993-0872

Common questions

Do I need a patent attorney based in California?

No. Every USPTO-registered patent practitioner is licensed to file applications on behalf of inventors in any state, regardless of where the practitioner's office is. Choosing a California-based practitioner can simplify in-person inventor signings, local meetings, and same-time-zone calls, but it is not a legal requirement.

How many patent attorneys are licensed in California?

9,567 active USPTO-registered patent practitioners list a California office address on the OEDCI roster. This includes both patent attorneys (who can also offer legal advice) and patent agents (who can prepare and file patents but not offer broader legal advice).

What is the difference between a patent attorney and a patent agent?

Both pass the USPTO Patent Bar and can prepare, file, and prosecute patent applications. Only patent attorneys also hold a state bar license, meaning they can additionally offer legal advice on infringement, licensing, and litigation strategy. Patent agents tend to charge less per hour and are common at large in-house IP departments.