{"data":{"id":"us/37-cfr-42.101","jurisdiction":"us","citation":"37 CFR 42.101","heading":"Who may petition for inter partes review.","body":"A person who is not the owner of a patent may file with the Office a petition to institute an inter partes review of the patent unless:\n(a) Before the date on which the petition for review is filed, the petitioner or real party-in-interest filed a civil action challenging the validity of a claim of the patent;\n(b) The petition requesting the proceeding is filed more than one year after the date on which the petitioner, the petitioner's real party-in-interest, or a privy of the petitioner is served with a complaint alleging infringement of the patent; or\n(c) The petitioner, the petitioner's real party-in-interest, or a privy of the petitioner is estopped from challenging the claims on the grounds identified in the petition.","path":["Title 37—Patents, Trademarks, and Copyrights","CHAPTER I—UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE","SUBCHAPTER A—GENERAL","PART 42—TRIAL PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD","Subpart B—Inter Partes Review"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-37.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:45Z","sha256":"a5a1c76fb6b8e34212af8e8e16462334c095071a16d0a08225a2a14b0cb3ce98","source_id":"us-cfr","stale":true,"prev":"us/37-cfr-42.100","next":"us/37-cfr-42.102"},"notice":"GroundRules: Original legal text. Not legal advice."}