New data from Patently-O shows that inter partes review (IPR) petitions collapsed in fiscal year 2026, which ended September 30. The Patent Office received about 450 petitions, a third of the 1,400 filed in FY2025 and even fewer than the 510 filed in FY2013, the program's first full year. The decline was abrupt: petitions ran about 110 a month through mid-2025, then fell to 61 in November 2025 and 30 in December, and have stayed between 15 and 46 a month ever since.
The series has been flat at roughly 30 petitions per month for nine months, with September 2026 coming in at 37. The author, Dennis Crouch, notes there is no sign of a rebound and also no sign of a further slide. The title of the post adds that the Patent Office's decisions to institute IPR proceedings are down by half as well, suggesting the drop is not just in filings but in the overall use of the review process.
The numbers represent a new normal for IPR, a procedure created by the America Invents Act to challenge patent validity. The sustained low rate, rather than a continued decline, may indicate that the remaining filings come from a narrower set of repeat users or cases where the strategic value of IPR remains high. The source does not speculate on causes, but the data point to a structural shift in how patent challenges are pursued.