California

Patent attorneys in California

California hosts 9,553 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 Codexis, Inc., Bozicevic, Field & Francis LLP, and Paramount Pictures Corporation.

Top cities in California

All practitioners in California

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

Lisa E Marks

Reg. 44901

Patent attorney

San Mateo, CA · 94401

Matthew C Marlowe

Reg. 55428

Patent attorney

South Pasadena, CA · 91030

510-529-6832

Timothy A Marquart

Reg. 63700

Patent attorney

Gilead Sciences

Foster City, CA · 94404

650-358-8046

Donald F. Marra

Reg. 79698

Patent attorney

Kim & Stewart LLP

San Jose, CA · 95113-1811

408-899-6442

Mark D. Marrello

Reg. 69378

Patent attorney

Imperium Patent Works, LLP

Pleasanton, CA · 94566

925-862-9972

Mark D Marsden

Reg. 57871

Patent attorney

San Diego, CA · 92103

619-708-0896

Eric F. Marsh

Reg. 72654

Patent attorney

Global Tel*Link

San Francisco, CA · 94111

415-300-4395

Philip William Marsh

Reg. 46061

Patent attorney

Arnold & Porter LLP

Palo Alto, CA · 94306

650-319-4733

Theodore A Marsh

Reg. 53272

Patent agent

Albany, CA · 94706

650-224-0223

Anthony J Marshall

Reg. 56406

Patent agent

Sheppard, Mullin, Richter & Hampton LLP

Palo Alto, CA · 94301

650-815-2692

Jeffrey B Marshall

Reg. 69724

Patent attorney

Los Angeles, CA · 90049

805-570-0018

K Lee Marshall

Reg. 51999

Patent attorney

Bryan Cave Leighton Paisner LLP

San Francisco, CA · 94111

415-675-3400

Ashley M. Martin

Reg. 80248

Patent agent

San Diego, CA · 92120

858-382-4877

Brandon C. Martin

Reg. 79423

Patent attorney

San Francisco, CA · 94116

520-403-0169

Bredt D Martin

Reg. 42842

Patent attorney

Bredt D. Martin Esq.

Canyon Country, CA · 91387

818-642-2802

Brian David Martin

Reg. 47771

Patent attorney

Long Beach, CA · 90803

Clinton J Martin

Reg. 56407

Patent attorney

Verily Life Sciences LLC

South San Francisco, CA · 94080

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?

9,553 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.