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 Keysight Technologies, INC., Indrajana Law Group, a PLC, and Van Pelt, Yi and James, LLP.

Top cities in California

All practitioners in California

John L Imperato

Reg. 40026

Patent attorney

Keysight Technologies, INC.

Del Mar, CA · 92014

408-236-1511

Michael B Indrajana

Reg. 65570

Patent attorney

Indrajana Law Group, a PLC

San Mateo, CA · 94402

650-597-0928

Jeffrey J. Inferrera· Jr

Reg. 79694

Patent agent

Shingle Springs, CA · 95682

916-990-2591

Laura Anne Ing

Reg. 56859

Patent agent

Van Pelt, Yi and James, LLP

Cupertino, CA · 95014

408-973-2581

Ann H. Inglett

Reg. 81860

Patent agent

Bayer CropScience LP

Woodland, CA · 95695

916-298-9942

James Weston Inskeep

Reg. 33910

Patent attorney

Inskeep Intellectual Property Group, Inc.

Torrance, CA · 90504

310-755-7800

Anthony M Insogna

Reg. 35203

Patent attorney

Jones Day

San Diego, CA · 92121

858-314-1130

Emerald S Iott

Reg. 82206

Patent attorney

WilmerHale

Palo Alto, CA · 94306

650-858-6000

Domenico L. Ippolito

Reg. 66058

Patent attorney

Schwegman Lundberg & Woessner LLP

San Jose, CA · 95113

408-278-4040

Adriana Irimia

Reg. 83673

Patent agent

La Jolla, CA · 92037

615-618-7133

Michael J Isaacs

Reg. 74055

Patent attorney

Prothena Corporation plc

South San Francisco, CA · 94080

650-837-8580

April E Isaacson

Reg. 52400

Patent attorney

Kilpatrick Townsend

San Francisco, CA · 94111

415-273-8306

Joel David Isaacson

Reg. 38191

Patent attorney

Alameda Health System

Oakland, CA · 94602

510-535-7474

Kevin W Isaacson

Reg. 63629

Patent attorney

San Jose, CA · 95118

801-362-9887

Raffi Isanians

Reg. 72905

Patent attorney

Los Angeles, CA · 90029

818-635-3843

A James Isbester

Reg. 36315

Patent attorney

Kilpatrick Townsend & Stockton, LLP

San Francisco, CA · 94111

415-576-0200

William H Ise'

Reg. 61208

Patent attorney

Newport Beach, CA · 92660

612-210-1414

Joshua D Isenberg

Reg. 41088

Patent attorney

JDI Patent

Fremont, CA · 94539

510-668-0965

Kanda Ishihara

Reg. 56607

Patent attorney

Veritas Technologies LLC

Mountain view, CA · 94043

650-933-1378

David M Ishimaru

Reg. 47676

Patent agent

Workday Inc.

Plesanton, CA · 94588

408-204-6154

Mikio Ishimaru

Reg. 27449

Patent attorney

Ishimaru & Associates

San Jose, CA · 95110

408-738-0592

Anna M Ison

Reg. 75359

Patent attorney

Wison Sonini Goodrich & Rosati

Palo Alto, CA · 94304-1050

650-846-93196

Lisa L Ison

Reg. 64067

Patent agent

Intuitive Surgical, Inc.

San Jose, CA · 95125

408-523-2100

Ned A Israelsen

Reg. 29655

Patent agent

Escondido, CA · 92029

760-705-8450

James A Italia

Reg. 56549

Patent attorney

Italia IP

Burbank, CA · 91505

818-973-2720

Bruce S Itchkawitz

Reg. 47677

Patent attorney

Knobbe Martens Olson and Bear, LLP

Irvine, CA · 92614

949-760-0404

Brian C Ito

Reg. 66690

Patent attorney

Facebook, Inc.

Menlo Park, CA · 94025

650-308-7859

Richard S. Ito

Reg. 61075

Patent attorney

Irvine, CA · 92618

949-300-3136

Richard Thomas Ito

Reg. 32242

Patent attorney

Nitto Denko Technical Corporation

Oceanside, CA · 92058

760-435-7006

Yoshiko Ito

Reg. 70437

Patent agent

McDermott Will & Emery LLP

Irvine, CA · 92612-2565

959-757-6359

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.