The Federal Circuit has overturned the USPTO’s rules on amendments in inter partes reviews (IPRs), holding that the petitioner, not the patentee, bears the burden of proof when the latter proposes new or amended claims. In an opinion issued on October 4, the majority in In re Aqua Products (2015-1177) ruled that the text of the America Invents Act (AIA) requires the petitioner to prove all grounds for unpatentability, including for amended claims, ruling in the alternative that the court owes no deference to the Patent Office’s rule to the contrary under the US Supreme Court’s decision in Chevron v. Natural Resources Defense Council. The majority also held that the Patent Trial and Appeal Board (PTAB) must consider and rely upon the entirety of the record when assessing the patentability of amended claims. Rehearing the case en banc after a panel found in favor of the petitioner, the Federal Circuit was divided in its conclusions, with four additional opinions—two expressly in dissent—issued along with the majority’s.