The picture emerging from the first half of 2026 is the completed migration of patent validity challenges from the Patent Trial and Appeal Board (PTAB) to ex parte reexamination. Petitions for inter partes review (IPR) fell to an all-time quarterly low of 57 in Q2 2026, while reexamination requests reached an all-time quarterly high of 336—surpassing even the 330 requests filed in Q3 2012, when requestors rushed to beat the September 16, 2012 AIA fee increase. Ex parte reexaminations accounted for 74.7% of post-grant filings in the first half of 2026, an almost exact inversion of the first half of 2025, when IPRs held a 72.9% share and reexaminations just 23.6%.
This migration is the continuing consequence of the procedural changes initiated by former Acting Director Coke Morgan Stewart and expanded by Director John Squires—including Director-level control of institution decisions and the October 2025 proposed rules codifying discretionary-denial practice—as detailed in previous Unified Patents reports, and reinforced by the Federal Circuit’s decision in In re Motorola Solutions, Inc., which insulated the Director’s discretionary institution authority from judicial oversight. The IPR institution grant rate, near 80% in January 2025, bottomed at 19.4% in August 2025 and was still just 21.5% in January 2026 before partially recovering to 47.4% in June 2026—though on a far smaller base of decisions. Measured on a trailing 12-month window, institution rates were still declining at mid-year: 27.2% against non-practicing entities (NPEs) and 41.4% against operating companies.
Two developments in the second quarter deserve careful attention. First, the quarterly institution rate against NPEs (47.0%) rose above the rate against operating companies (35.6%) for the first time since the discretionary-denial surge began—reversing the pattern documented in our 2025 and Q1 2026 reports. Second, monthly reexamination requests fell from a peak of 136 in May to 79 in June, the first notable retreat since the surge began; whether this reflects the USPTO’s April 2026 “pre-order” procedure—which gives patent owners a fee-free opportunity to oppose a reexamination request before a Substantial New Question determination—will become clearer in Q3.
Other takeaways from the first half of 2026:
District court patent filings totaled 1,921 in the first half of 2026, down 18.4% from the first half of 2025. Q2’s 1,007 new cases, however, were in line with quarterly volumes over the past several years—the upheaval at the USPTO has had little visible effect on district court litigation.
NPEs filed 50.5% of district court patent cases in the first half of 2026, but their share slipped to 48.6% in Q2—the first quarter below 50% since Q1 2018.
The E.D. Tex. and W.D. Tex. together drew roughly 37% of all patent filings; the E.D. Tex. alone accounted for 46.6% of NPE filings.
Pending PTAB matters fell to 696 at the end of June 2026, just 36.2% of the November 2018 peak of 1,923.
Google was the top PTAB petitioner (17 petitions), and six of the ten most-frequently challenged patent owners at the PTAB were NPEs.
High tech remained the center of gravity in both forums: 69.2% of PTAB petitions and 54.4% of district court cases. NPEs filed 88.3% of high-tech district court cases and were the target of 71.7% of high-tech PTAB challenges.
District Court, PTAB, and Reexamination Filings by Quarter: PTAB filings continued their steep decline through the first half of 2026 and were largely supplanted by ex parte reexaminations, which set a new all-time quarterly record in Q2. The dramatic swings in PTAB and reexamination volume have had little visible effect on district court litigation: parties filed 1,007 new patent cases in Q2 2026, in line with quarterly volumes over the past several years.
District Court, PTAB, and Reexamination Filings by Month: Requests for ex parte reexamination fell to 79 in June 2026—the low for the year so far, and the same volume recorded in January—after peaking at 136 in May. The June retreat follows the USPTO’s April 2026 announcement of the new “pre-order” procedure allowing patent owners to oppose reexamination requests before a Substantial New Question determination. New district court litigation, meanwhile, jumped from 280 cases in May to 378 in June.
Adoption of the New "Pre-Order" Procedure: The USPTO's April 2026 "pre-order" procedure gives patent owners a fee-free, 30-page opportunity to argue against a Substantial New Question of patentability before an ex parte reexamination is ordered. Patent owners moved quickly to use it: of the 234 reexamination requests filed between April 6 and June 11, 2026, patent owners filed a pre-order challenge in 97—roughly 42%. Whether this early uptake begins to dampen reexamination volume, which retreated from 136 requests in May to 79 in June, will be a key trend to watch in the second half of 2026.
Post-Grant Proceedings in the First Half of 2026: Patent challenge dynamics flipped between 2025 and 2026. In the first half of 2026, ex parte reexaminations accounted for 74.7% of post-grant filings (594 requests), with IPRs at 21.9% (174 petitions) and post-grant reviews (PGRs) at 3.4% (27 petitions). In the first half of 2025, IPRs (698) led at 72.9% while reexaminations (226) made up just 23.6%. On a quarterly basis, reexamination requests have now outnumbered all PTAB petitions combined for three consecutive quarters. Notably, PGR volume has held steady at 13–15 petitions per quarter even as IPR filings collapsed, lifting the PGR share of PTAB petitions from 4.1% in Q2 2025 to 18.6% in Q2 2026.
PTAB Filings by Quarter: Petitions for inter partes review fell to an all-time quarterly low of 57 in Q2 2026, down 51.3% from Q1 2026 and 83.8% from Q2 2025. Total PTAB petitions for the first half of 2026 stood at 201, a 72.5% decline from the 732 filed in the first half of 2025.
Requests for Ex Parte Reexamination: Requests for ex parte reexamination reached an all-time quarterly high of 336 in Q2 2026, a 30.2% increase over Q1 2026 and a 148.9% increase over Q2 2025. The previous record—330 requests in Q3 2012—was set during the “fee rush” preceding the September 16, 2012 AIA fee increase, when 241 requests were filed in the first two weeks of September alone. Q2 2026 edged that record by 1.8%, and did so on ordinary-course filings rather than a one-time procedural deadline.
Top Reexamination Requestors. The surge in ex parte reexamination in the first half of 2026 was led by large operating companies rather than by dedicated challengers. Samsung was the most active requester by a wide margin, filing 61 of the 594 reexamination requests (10.3%), followed by Apple (28) and Unified Patents (25). Technology and semiconductor companies—Cisco, Intel, SK Hynix, NXP, Micron, Google, and Tesla among them—filled out the top ranks. The prominence of these petitioners, many of them among the most active PTAB petitioners historically, reinforces the broader picture: as institution rates at the PTAB fell, the operating companies that once relied on inter partes review shifted their validity challenges to reexamination.
Top Reexam Targets (Patent Owners). The patents most frequently challenged through ex parte reexamination in the first half of 2026 were split fairly evenly between non-practicing entities and operating companies. Six of the eleven most-challenged owners were NPEs—led by Massively Broadband LLC (16), K.Mizra (12), and Mosaid Technologies (11)—while five were operating companies, including Cleerly (12), Clark Equipment (10), and Magic Leap (8). The split shows that reexamination is being used not only against NPEs but also in OpCo-vs-OpCo disputes.
PTAB Procedural Denials vs. Requests for Ex Parte Reexamination: PTAB procedural denials fell 67.9% between Q1 and Q2 2026 (156 to 50), consistent with the sharply reduced volume of petitions reaching an institution decision. Comparing the first half of 2025 to the first half of 2026 (141 to 206), however, procedural denials rose 46.1% while reexamination requests (226 to 594) rose 162.8%—the tactical migration from AIA trials to reexamination that began in 2025 accelerated in 2026.
IPR Filings vs. Institution Rate: The IPR institution grant rate, which stood at 81.8% in January 2025, fell to an all-time monthly low of 19.4% in August 2025 and was still just 21.5% in January 2026. Over the first half of 2026 the rate partially recovered, reaching 47.4% in June—though on a much smaller base of decisions. The collapse in grant probability has been mirrored by a collapse in demand: monthly IPR filings fell from 131 in January 2025 to just 22 in June 2026.
Pending PTAB Petitions & Procedural Denials: With fewer petitions coming in and elevated denials clearing the docket, the volume of open matters at the PTAB continued to contract. At the end of June 2026, only 696 cases remained pending—36.2% of the all-time peak of 1,923 reached in November 2018.
PTAB Institution Rate Against NPEs vs. Operating Companies (Trailing 12 Months): Measured on a rolling 12-month window, institution rates continued to decline for both NPEs and operating companies through the first half of 2026. As of the end of Q2, petitions against NPE-owned patents were instituted 27.2% of the time, compared to 41.4% for petitions against operating companies. The institution rate is (the number of institutions during the 12-month sliding window) ÷ (the total number of institutions and denials during that same period).
Institution Rate: NPE vs. OpCo in the First Half of 2026: For institution decisions rendered in the first half of 2026, the rate for IPR petitions against NPEs (31.7%) trailed the rate against operating companies (39.5%).
Institution Rate by Month: The Q2 Reversal: The half-year gap conceals a sharp reversal within the period. In Q1 2026, the institution rate against NPEs was 24.1%, well below the 41.7% rate against operating companies. In Q2, the relationship flipped: 47.0% against NPEs versus 35.6% against operating companies, with the crossover first appearing in April.
Filing Trends in PTAB by Entity Type: As overall PTAB volume fell, petitions against both entity types dropped in tandem: just 35 petitions against operating companies and 34 against NPEs in Q2 2026.
PTAB Petitions by Industry: Despite the decline in overall filings, high-tech patents remained the PTAB’s center of gravity, drawing 69.2% of all petitions in the first half of 2026.
Filing Trends in High Tech at the PTAB by Entity Type: Within high tech, NPEs were the target of 71.7% of PTAB challenges in the first half of 2026.
Top 10 PTAB Petitioners: Google was the top petitioner at the PTAB in the first half of 2026 with 17 petitions, followed by Cisco (14), Tesla (13), and Apple (13).
Top 10 PTAB Patent Owners: Although institution rates against NPE-owned patents ran well below those against operating companies through most of 2025 and the first quarter of 2026, NPEs still accounted for six of the ten most-frequently challenged patent owners at the PTAB in the first half of 2026, led by Qomplx (8 petitions) and Bulletproof Property Management LLC (7).
Filing Trends in District Court by Entity Type: NPEs filed 50.5% of district court patent cases in the first half of 2026 (970 of 1,921). In Q2, however, the NPE share slipped to 48.6% (489 NPE cases versus 477 operating-company cases)—the first quarter in which NPEs accounted for less than half of new district court patent cases since Q1 2018.
Top 10 District Court Plaintiffs. ABC IP, LLC, Rare Breed Triggers, Inc., and RBTM, LLC, grouped together, were the most active district court patent plaintiff in the first half of 2026, with 102 filings—roughly 5% of all patent cases filed over the period and more than three times the next-most-active plaintiff. The three are affiliates in a single, coordinated campaign to enforce patents relevant to the firearms-industry, as opposed to the high-technology litigation that fills the rest of the rankings. The eight next-most-active plaintiffs were all NPEs: Portus (29), Patent Armory (21), Key Patent Innovations (17), Lone Star Document Management (16), VDPP (16), ContentNexus (15), Near Field Electronics (15), and AML IP (14).
Top 10 District Court Defendants. The most frequently named district court patent defendants in the first half of 2026 were large technology manufacturers, led by Samsung (34), Apple (25), Google (22), and Amazon (19), with TCL (14), Meta (11), and Microsoft (11) close behind. The second notable group is generic-pharmaceutical manufacturers—Zydus (18), Lupin (11), and Cipla (9).
Top District Courts for Patent Litigation: The E.D. Tex. and W.D. Tex. together accounted for roughly 37% of patent litigation filed in the first half of 2026. Beyond Texas, the D. Del., N.D. Ill., and D.N.J. remained the most frequent venues.
Top District Courts for NPE Filings: The E.D. Tex. alone drew 46.6% of NPE district court filings in the first half of 2026. Other leading NPE venues were the W.D. Tex., D. Del., N.D. Cal., and N.D. Tex.
District Court Litigation by Industry: High-tech cases accounted for 54.4% of district court patent litigation in the first half of 2026, with medical/pharmaceutical cases at 11.7%—both broadly consistent with their trailing three-year averages of 57.2% and 12.6%.
Filing Trends in High Tech in District Court by Entity Type: NPEs filed 88.3% of high-tech district court patent cases in the first half of 2026, even though they filed only about half of district court patent cases overall. NPE litigation remains overwhelmingly concentrated in high tech (93.4% of NPE cases), while operating-company litigation largely is not (11.4% high tech).
Definitions
Proceedings
PTAB = The Patent Trial and Appeal Board of the United States Patent and Trademark Office (USPTO), which hears the trial proceedings created by the America Invents Act (AIA): IPR, PGR, and (historically) CBM.
Inter Partes Review (IPR) = A trial proceeding before the PTAB, available since September 16, 2012, in which any party other than the patent owner may challenge issued patent claims as anticipated or obvious (35 U.S.C. §§ 102/103) based on patents and printed publications.
Post-Grant Review (PGR) = A trial proceeding before the PTAB in which a petitioner may challenge a recently issued patent (within nine months of grant) on any ground of invalidity.
Covered Business Method Review (CBM) = A transitional PTAB proceeding for covered business method patents; new CBM petitions ended in September 2020. CBM appears only in the historical portions of the charts.
Ex Parte Reexamination (Reexam) = A proceeding before the USPTO’s Central Reexamination Unit (CRU), available since 1981, in which any party (or the Director) may request reexamination of an issued patent based on patents and printed publications. If the request raises a Substantial New Question of patentability, reexamination is ordered; the requester does not participate after the request stage (hence ex parte).
SNQ = Substantial New Question of patentability — the threshold showing required for the USPTO to order an ex parte reexamination.
Metrics
Institution Rate = (the number of institutions during the stated window) ÷ (the total number of institutions and denials during that same window). Where a chart is labeled with a 12-month sliding window, both counts are taken over the trailing 12 months ending on the date shown.
Procedural (Discretionary) Denial = A denial of institution on non-merits grounds — for example, discretionary denial in view of parallel litigation or prior challenges — as distinct from a denial on the merits of the asserted grounds. Unless a chart states otherwise, “procedural denials” exclude merits denials.
Sotera Stipulation = A petitioner’s stipulation not to pursue in district court the invalidity grounds raised, or that reasonably could have been raised, in its IPR petition — historically offered to avoid discretionary denial based on parallel litigation.
Schedule A Defendant = A defendant identified only on a sealed “Schedule A” attached to the complaint — a device commonly used in suits against large numbers of online sellers, and frequent in design-patent filings. Where noted, top-defendant rankings are reported excluding Schedule A defendants.
Entities
Non-Practicing Entity (NPE) = A company that derives the majority of its total revenue from patent licensing or assertion activities rather than from making or selling products or services. Reported NPE totals include the three subtypes below.
NPE (Patent Assertion Entity) = An entity whose primary activity is licensing or asserting patents and that acquired most of its patents from another entity.
NPE (Small Company) = An entity whose original activity was providing products or services, but which is now primarily focused on monetizing its own patent portfolio.
NPE (Individual) = An entity owned or controlled by an individual inventor and primarily focused on monetizing that inventor’s patents.
NPE Aggregator = An entity that controls or owns two or more NPEs.
Operating Company (OpCo) = A company that derives most of its total revenue from product sales or services. May be an SME or a large company.
Other Entity = Universities, non-profits, governments, and non-governmental organizations (NGOs).
Third-Party Litigation Funding (TPLF) = Financing of a patent assertion by a third party — any party with a financial interest in the outcome other than the asserting entity itself. Cases are flagged as TPLF where evidence of such funding appears in court filings or public documents.
Sectors
High-Tech = Technologies relating to software, hardware, and networking.
Medical = Technologies relating to pharmaceuticals, medical devices, and health-related technologies.
Other = Technologies relating to mechanical devices, packaged goods, sporting equipment, and any other area outside high-tech and medical.
Venues
District courts are abbreviated in the conventional reporter style: a district prefix (N.D., S.D., E.D., W.D., C.D., or D. for districts covering a whole state) followed by the state. Venues appearing in this report include:
E.D. Tex. = Eastern District of Texas
W.D. Tex. = Western District of Texas
N.D. Tex. = Northern District of Texas
D. Del. = District of Delaware
N.D. Ill. = Northern District of Illinois
D.N.J. = District of New Jersey
N.D. Cal. = Northern District of California
C.D. Cal. = Central District of California
S.D.N.Y. = Southern District of New York
Methodology
This report includes all District Court, PTAB, and ex parte reexamination cases between January 1, 2012 and June 30, 2026.
The total number of reported cases can vary based on what is included. Unified made its best attempt to eliminate mistaken, duplicative, or changed-venue filings, so totals may vary slightly compared to other reporting entities. Statistics include litigations initiated by NPEs and declaratory judgment (DJ) actions initiated by operating companies against NPEs.
Unified strives to accurately identify NPEs through all available means, such as court filings, public documents, and product documentation.
Quarterly and half-year figures reflect Unified’s data as of the report’s data pull date; small revisions to previously published quarterly figures can occur as late-loading records settle.