When can prior art or Section 301 written statements be filed for a patent?
Prior art or Section 301 written statements can be filed “at any time during the period of enforceability of a patent.” As stated in MPEP 2204:
“Submissions may be filed ‘at any time’ under 35 U.S.C. 301. However, this period has been defined by rule (37 CFR 1.501(a)) to be ‘any time during the period of enforceability of a patent.'”
This period typically includes the term of the patent plus six years, accounting for the statute of limitations for infringement actions.
To learn more:
Topics:
MPEP 2200 - Citation Of Prior Art And Ex Parte Reexamination Of Patents,
MPEP 2204 - Time For Filing Prior Art Or Section 301 Written Statements,
Patent Law,
Patent Procedure