Ten Things to Know About California Intellectual Property Law in 2026

California has witnessed a watershed in intellectual property law and policy over the last two years. A new administration taking office in Washington, DC in 2025 ushered in a different patent policy focus, moving away from Patent Office litigation and giving a boost to patent owners. The following discusses some of the latest trends in intellectual property impacting California.

California’s busy federal courts have a strong reputation for their expertise in patent and intellectual property law, and are consistently among the top ten patent courts in the USA by patent filing data. What is less discussed are California courts’ strong efforts at gatekeeping patent cases. Each of the Northern District, Central District and Southern District of California federal courts grant motions to dismiss and for summary judgment in patent cases at well above the national averages.

These trends, as well as how recent patent policy shifts over the past two years are impacting California, are discussed below. The next two years promise even more surprises ahead.

California’s popular patent courts

For more than two decades, US patent cases have tended to cluster in California and a handful of other federal district courts. Given California’s leadership in innovation and dynamic USD4 trillion economy, it is no surprise that California’s federal courts, including its Northern, Central and Southern Districts, are consistently ranked among the top patent courts.

In 2025, more than 70% of US patent cases were filed in the following courts, listed in order of increasing popularity:

• Southern District of California encompassing San Diego and neighbouring Imperial County;
• Northern District of California encompassing San Francisco and Silicon Valley;
• Central District of California covering Los Angeles and its neighbouring counties;
• District of New Jersey;
• Northern District of Illinois including Chicago and its environs;
• District of Delaware;
• Western District of Texas from El Paso to Austin; and
• Eastern District of Texas spanning counties east of Dallas and Houston.

According to case analytics data from DocketNavigator®, case filings increased or held relatively steady from 2024 to 2025 across all of these popular patent courts. This is also true in California’s federal courts:

• Southern District of California: 26 new case filings in 2025 compared to 24 in 2024;
• Northern District of California: 106 new case filings in 2025 compared to 115 in 2024;
• Central District of California: 192 new case filings in 2025 compared to 204 in 2024;
• District of New Jersey: 220 new case filings in 2025 compared to 230 in 2024;
• Northern District of Illinois: 412 new case filings in 2025 compared to 428 in 2024;
• District of Delaware: 526 new case filings in 2025 compared to 394 in 2024;
• Western District of Texas: 531 new case filings in 2025 compared to 374 in 2024; and
• Eastern District of Texas: 1,247 new case filings in 2025 compared to 1,071 in 2024.

California’s continued leadership In IP disputes

California’s federal courts are known for their talented pool of judges experienced in patent cases, which explains its popularity for filing and transferring cases there. Indeed, the Northern District of California, which encompasses Silicon Valley, was the first US federal court to introduce local rules governing specific procedures tailored to patent cases. Its rules have been adopted and emulated by courts and judges across the country.

California’s gatekeeping of patent cases

California judges have demonstrated a leadership role in gatekeeping patent cases by carefully ensuring that only meritorious patent claims are tried. For example, three of California’s district courts grant motions to dismiss at rates far above the national average.

From 1 January 2025 to 1 June 2026, the national average for granting partial or complete motions to dismiss patent complaints was 26.8%, according to data from DocketNavigator®. Each of the following California courts exceeded that rate in granting motions to dismiss, some by wide margins:

• Southern District of California: 68.8% of 16 motions to dismiss decided;
• Northern District of California: 56% of 91 motions to dismiss decided; and
• Central District of California: 35.1% of 74 motions to dismiss decided.

This is also seen in grant rates for summary judgment motions resolving disputes before trial. The national rate for granting partial or entire motions for summary judgment in patent cases stood at 28%, according to DocketNavigator® data spanning the same time period of 1 January 2025 to 1 June 2026. Each of these three districts again exceeded the national average:

• Southern District of California: 50% of 8 summary judgment motions decided;
• Northern District of California: 38.2% of 68 motions to dismiss decided; and
• Central District of California: 39.6% of 53 motions to dismiss decided.

The above statistics demonstrate that California judges are maintaining a strong role in removing weak or undisputed issues from patent jury trials, thereby supporting innovation.

California and other preferred courts

California’s strong gatekeeping role has earned it favour with innovative companies and Fortune 500 companies facing an onslaught of patent filings.

The Eastern District of Texas and District of Delaware have long been the preferred courts for many patent owners. In recent years, the Western District of Texas has vaulted into one of the top spots following the nomination and confirmation of Judge Albright. However, Judge Albright’s April 2026 announcement of his retirement from the federal Bench is expected to significantly reduce the popularity of that Texas court.

The rise of US patent litigation

The last several years have shown a consistent increase in patent cases filed in California and other federal courts. In particular, the number of patent cases filed in US district courts totalled 3,120 and 3,799 in 2023 and 2024, respectively. The trajectory accelerated further in 2025, with a total of 4,532 cases filed, according to data from DocketNavigator®. This represents a 45% jump in patent litigation filings between 2023 and 2025.

These patent litigation trends are expected to continue in 2026. While patent filings in the first quarter of 2026 slowed, we expect the pace of filings in California for 2026 to maintain or even exceed that of recent years. Changes in national patent policy, re-examination, and global interest in patent litigation (each discussed below) are fuelling these increased filings.

The patent policy pendulum swings back

California intellectual property attorneys are used to the pendulum of US patent policy gradually swinging back and forth. The pendulum dramatically reversed over the past 18 months, as the erstwhile popularity of inter partes reviews (IPRs) plummeted. This drop in IPRs is leading to an increase in patent litigation in California and other courts.

IPRs came into being when the last round of patent reform 15 years ago provided a new avenue for resolving patent disputes at the US Patent Office. Previously, patent validity had been determined either as part of federal court patent infringement lawsuits or through slower Patent Office ex parte or inter partes re-examinations.

The 2011 America Invents Act (AIA) created additional options for streamlined patent validity challenges at the Patent Office, notably IPRs. This new federal law allowed anyone to challenge the validity of an issued patent for anticipation or obviousness based on prior art patents and printed publications. With limited discovery, a lower burden of proof and a 12-month statutory deadline, IPRs offered a faster and cheaper method for deciding patent validity disputes.

When the Patent Trial and Appeal Board opened for business in late 2012, IPR filings surged, and they have maintained their popularity ever since. In fiscal year 2024, the Patent Office ordered trials in response to about 68% of IPR petitions requesting them.

That has now all changed. New policy directives from Washington, DC aimed at strengthening US innovation have discouraged IPRs and are pushing validity disputes elsewhere, including to California and other federal courts or to traditional re-examination, as discussed in the sections below.

In October 2025, the newly confirmed Patent Office Director began actively deciding IPR petitions, turning away many challenges. The number of IPR trials ordered dropped to their lowest level since the AIA established them.

As a result, IPR filings have dropped precipitously. Only 11 petitions were filed in April 2026, far beneath the average rate of 80 to 130 petitions per month during the preceding five years. See, for example, Dennis Crouch, Decimation: Ex Parte Reexamination Eclipses the IPR, https://patentlyo.com/patent/2026/05/decimation-ex-parte-reexamination-eclipses-the-ipr.html (last visited 16 June 2026).

Re-examination resurges

Another fast-evolving landscape impacting California involves conventional ex parte re-examinations. With IPRs in retreat, the Patent Office is witnessing a surge in third-party re-examination requests and concurrent requests to stay parallel patent litigation involving other patents in California and other courts.

Like IPRs, re-examinations also allow third parties, as well as patent owners themselves, to ask the Patent Office to reconsider the validity of issued US patents. The process is initiated by submitting a request asking a patent examiner to evaluate whether the prior art raises a “substantial new question of patentability”.

Unlike IPRs, however, once initiated, the re-examination proceeds ex parte without the participation of any third-party requestor or strict statutory deadline. The re-examination then proceeds somewhat like the original patent examination, with the examiner engaging directly with the patent owner by rejecting, amending and/or allowing claims.

Recent data shows that ex parte re-examination requests rose sharply in 2025, concurrent with IPR requests plunging. According to Patent Office official data, ex parte re-examination requests had previously held steady, with about 50 to 100 requests filed per quarter since fiscal year 2022. This began to suddenly change at the end of 2025. The first and second quarters of fiscal year 2026 saw over a 200% spike in re-examination request filings: approximately 275 in Q1 and 250 in Q2 2026, compared to approximately 95 and 75 requests in Q1 and Q2 of 2022, respectively. See Reexamination Statistics, https://www.uspto.gov/learning-and-resources/statistics/reexamination-information (last visited 16 June 2026).

As one commentator put it, patent challengers are getting the message that, without IPRs, “what the data show is that re-examination is better than nothing”. See https://patentlyo.com/patent/2026/05/decimation-ex-parte-reexamination-eclipses-the-ipr.html (last visited 16 June 2026).

However, this trend may not last long. In April 2026, the Patent Office announced “a new process” for patent owners to submit pre-order papers explaining why a re-examination request does not establish a substantial new question of patentability and thus should not be ordered. See Pre-order Procedure regarding Substantial New Question determination in ex parte reexamination proceedings, https://www.uspto.gov/sites/default/files/documents/og-preorder-snq-apr2026.pdf (last visited 16 June 2026). This new policy may herald that the Patent Office’s IPR retrenchment may soon impact re-examination as well.

Expanding global interest in California and US patent litigation

Patent litigation continues to attract special interest because of the steady headlines of large jury verdicts in patent cases. Over the past two years, many plaintiffs, including non-practising entities, have celebrated nine- or ten-figure damages awards.

For example, Netlist obtained a USD445 million verdict against Micron in 2024, which was largely confirmed on appeal. Yet the USD874 million jury verdict in General Access Solutions v Verizon evaporated during post-trial motions when the verdict was vacated.

Indeed, data from Unified Patents found lawsuits brought by non-practising entities show that “district court filings jumped 21.6% in 2025 compared to 2024”, compared to only a 12% jump in overall patent case filings. See Patent Dispute Report: 2025 in Review, https://www.unifiedpatents.com/insights/2026/1/13/patent-dispute-report-2025-in-review (last visited 16 June 2026).

Attracted by potential returns, the landscape of US patent cases has been transformed over the past decade by the arrival of outside investors and private equity funding patent lawsuits, seeking returns independent of stock market performance and other investments. This interest is now global, with the reported participation of international investors and sovereign wealth funds.

As the economic outlook dims, we expect established domestic and international companies to also monetise their US patent portfolios in an effort to bolster their economic performance. This will lead to increases in patent litigation in California and elsewhere.

Design patents on the rise

Industrial design only continues to grow in importance among California’s innovators. The past ten years have seen continued growth in design patent filings. Just a decade ago, Patent Office data showed just over 40,000 design patent applications were filed with it in fiscal year 2016. That number has grown significantly to over 65,000 design patent applications filed in 2025 alone. See Design Data May 2026, https://www.uspto.gov/dashboard/patents/design.html (last visited 16 June 2026).

This sustained interest in design patents has also gained traction at the appellate level. In 2024, the Federal Circuit issued its first en banc decision in a design patent case in more than a decade.

Sixteen years after the Federal Circuit’s 2008 Egyptian Goddess decision, the court’s 2024 opinion in LKQ Corporation v GM Global Technology overturned its long-standing strict Rosen-Durling decision and held that design patent obviousness must be evaluated under the more flexible standard articulated by the Supreme Court in KSR.

Although LKQ potentially unlocked a broader set of prior art for design patents, the decision nonetheless coincided with an explosion of new design patent cases. In 2023, the year before the LKQ decision, 155 design patent infringement cases were filed nationwide. Yet that number jumped by over 250% to 564 new case filings in 2024. The trend largely held in 2025, which saw 455 new case filings involving design patents.

Changes at the Patent Appeals Court

The last two years have also seen changes at the Court of Appeals for the Federal Circuit sitting in Washington, DC. The Federal Circuit has nationwide jurisdiction over certain specific areas of law, including all patent appeals from federal courts and administrative agencies. As a result, appeals from patent cases filed in all California federal courts are heard by the Federal Circuit, and not the regional Ninth Circuit Court of Appeals that typically reviews appeals from California federal courts.

Intellectual property appeals make up about 65% of the Federal Circuit’s pending caseload. Unlike some other regional circuit courts of appeals, the Federal Circuit’s Rule 36 practice permits the appellate court to issue one-word affirmances without a written opinion on the merits. This allows the court to efficiently dispose of clear-cut cases with no precedential value.

However, the court has been criticised in recent years because its Rule 36 affirmances have been used to resolve about 40% of Patent Office appeals and 17% of district court intellectual property appeals. Over the past decade, numerous parties have unsuccessfully sought Supreme Court review of the Federal Circuit’s Rule 36 dispositions.

The past year of 2025 notably brought a sharp decline in the Federal Circuit’s Rule 36 practice. According to our own forthcoming study, Rule 36 affirmances from Patent Office appeals declined by about 40% last year, from 40% to just 24% of these appeals in 2025.

We observed even steeper declines of about 65% in district court appeals. In 2025, the Federal Circuit issued Rule 36 affirmances in just 6% of its dispositions of district court cases, compared to a previous rate of 17%, instead favouring issuing non-precedential opinions. We are continuing to track these trends at the Federal Circuit.

Where we are headed

The only thing that has a remained a constant in intellectual property litigation in California is change. As technology evolves and patent law adapts alongside it, sophisticated attorneys and their clients must do more than keep up. The playbook from last year will probably not work this year.

After watching these policies play out over the past three decades across California, our experienced hands and crystal balls are warmed up and ready. We look forward to all of the rapid changes, and the opportunities they present, arriving in the near future.