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 Nixon Peabody LLP, INTERNATIONAL KNOWLEDGE ASSET OFFICE, and Law Office of Eric G. Masamori.

Top cities in California

All practitioners in California

Eric S Marzluf

Reg. 27454

Patent attorney

La Quinta, CA · 92253

215-327-2245

Keiji Masaki

Reg. 45322

Patent agent

INTERNATIONAL KNOWLEDGE ASSET OFFICE

Irvine, CA · 92612

949-954-0811

Eric G Masamori

Reg. 46360

Patent attorney

Law Office of Eric G. Masamori

Walnut Creek, CA · 94598

925-947-1002

Mary A Mashruwala

Reg. 61707

Patent agent

Prolacta Bioscience

Duarte, CA · 91010

832-496-5979

John C Masiewicz

Reg. 60597

Patent agent

Western Digital

San Jose, CA · 95138-1857

949-363-4259

Victoria K Maskiewicz

Reg. 42750

Patent agent

Loma Linda University

Loma Linda, CA · 92350

909-558-9754

David M Mason

Reg. 42846

Patent agent

Align Technology, Inc.

San Jose, CA · 95131

408-470-1000

Diane J Mason

Reg. 43777

Patent attorney

Bullivant Houser Bailey PC

San Francisco, CA · 94108-2823

415-352-2758

Terrance Mason

Reg. 53280

Patent agent

Studio City, CA · 91604

818-808-3147

Kenneth M Massaroni

Reg. 33015

Patent attorney

Seagate Technology Plc

Cupertino, CA · 95014

952-402-8447

Cory A. Massey

Reg. 80349

Patent agent

Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.

San Diego, CA · 92130

858-314-1578

Ofer I Matalon

Reg. 39439

Patent attorney

Santa Rosa, CA · 95405

310-403-1233

Shirley A. Matcha

Reg. 82666

Patent attorney

Mountain View, CA · 94040

727-515-9354

Lois W. Matelan

Reg. 61625

Patent attorney

Lois W. Matelan

Glendale, CA · 91206

646-338-7010

Kuruvilla Mathen

Reg. 71146

Patent attorney

2020 Bancroft Way, # 224

Berkeley, CA · 94704

510-868-8716

Renjith Mathew

Reg. 800137

Limited recognition

Nixon Peabody LLP

San Francisco, CA · 94111

415-849-5613

Thomas K Mathew

Reg. 74248

Patent attorney

InterVenn Biosciences

South San Francisco, CA · 94080

512-934-8373

Christopher Anthony Mathews

Reg. 35944

Patent attorney

Quinn Emanuel Urquhart Oliver & Hedges

Los Angeles, CA · 90017

213-443-3000

Glenn T Mathews

Reg. 66177

Patent agent

NokiaTechnologies, Inc

Sunnyvale, CA · 94086

408-737-0900

Duane H Mathiowetz

Reg. 33420

Patent attorney

Practus LLP

San Francisco, CA · 94111

415-501-0350

Mark P. Mathison

Reg. 57556

Patent attorney

KILPATRICK TOWNSEND & STOCKTON LLP

Walnut Creek, CA · 94596

925-472-5000

Maneesh K. Mathur

Reg. 71512

Patent attorney

Apple Inc.

Cupertino, CA · 95014

408-996-1010

John R. Matic

Reg. 72977

Patent agent

Matic IP Services

Kingsburg, CA · 93631

925-413-3360

Nathan T Matsubara

Reg. 63943

Patent attorney

El Cerrito, CA · 94530

510-260-0575

James E Matsuura

Reg. 64861

Patent agent

San Diego, CA · 92101

970--22-2-5114

Darren T. Matt

Reg. 61626

Patent attorney

San Diego, CA · 92101

415-794-7539

Natalia S Mattan-Hung

Reg. 71386

Patent agent

Nixon Peabody LLP

Los Angeles, CA · 90071

213-629-6123

Bradford Earl Mattes

Reg. 36862

Patent attorney

Kleinberg & Lerner, LLP

Los Angeles, CA · 90067

310-557-1511 EXT. 3016

Benjamin Bainbridge Matthew

Reg. 62430

Patent attorney

Los Angeles, CA · 90067

310-556-6752

Mehlin D Matthews

Reg. 46127

Patent agent

Polaris Research

Saratoga, CA · 95071

408-938-9060 X127

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.