When was inter partes reexamination replaced by inter partes review?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Inter partes reexamination was replaced by inter partes review on September 16, 2012, as a result of the Leahy-Smith America Invents Act (AIA). The MPEP states: “Section 6(c) of the AIA replaced the inter partes reexamination process, effective September 16, 2012, with a new inter partes review process, such that on or after September 16, 2012 the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review.” There was a one-year transition period from September 16, 2011, to September 15, 2012, during which inter partes reexamination requests were still accepted under a revised standard.