USPTO Clarifies Test for Indefiniteness in AIA Post-Grant Proceedings

One requirement of patent law is that a patent’s “specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.” 35 U.S.C. § 112(b). The aforementioned is the basis for indefiniteness challenges to patent claims, which can be the subject of various proceedings before the Patent Trial and Appeal Board (PTAB) of the United States Patent and Trademark Office (USPTO), including in post-grant proceedings, and also patent litigation before the federal district courts.  

Until recently, the PTAB and district courts have analyzed indefiniteness under two different legal standards, which were generally referred to as the Packard and Nautilus standards, respectively. Under Packard, a claim is indefinite “when it contains words or phrases whose meaning is unclear.” In re Packard, 751 F.3d 1307, 1310 (Fed. Cir. 2014). In contrast, under Nautilus, a “patent is invalid for indefiniteness if its claim, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.” Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 901 (2014).  

On January 6, 2021, the USPTO ended the use of different indefiniteness standards in post-grant proceedings, publishing a Memorandum that clarified that the PTAB shall follow Nautilus in America Invents Act (AIA) post-grant proceedings. See USPTO, Approach to Indefiniteness under 35 U.S.C. § 112 in AIA Post-grant Proceedings (“Memorandum”) (Jan. 6, 2021), https://www.uspto.gov/sites/default/files/documents/IndefinitenessMemo.pdf. The USPTO did this after recognizing that having two different legal standards led to confusion as to which legal standard to argue before the PTAB, with some practitioners arguing either or both standards. See Memorandum at 4. The USPTO recognized that there were fundamental differences between its approach and the district court’s approach. Memorandum at 3. In the past, the Federal Circuit had also declined to decide which standard applies in the post-grant review process. See Tinnus Enters., LLC v. Telebrands Corp., 733 F. App’x 1011, 1018 (Fed. Cir. 2018).

The memorandum explained that the USPTO was spurred to conform its standard with that of the district courts by the USPTO’s 2018 decision to align the claim construction standard used in AIA post-grant proceedings, thus shifting the PTAB from using the broadest reasonable interpretation (BRI) standard to the district courts’ Phillips standard. See 37 C.F.R. §§ 42.100(b), 42.200(b). The memorandum stated that the USPTO decided to also change the indefiniteness standard because, in part, “indefiniteness questions are generally considered as part of the claim construction process.” Memorandum at 5.

Thus, the memorandum aligns the indefiniteness standard between the PTAB and district courts, such that both will now be using the same Nautilus standard for indefiniteness. According to the memorandum, “the rule change promotes consistency and efficiency between coordinate branches of the government that analyze the same claims in co-pending proceedings.” Id. at 4. The memorandum further explained that the change will “lead to greater uniformity and predictability, improve the integrity of the patent system, and help increase judicial efficiency” by “eliminating the differences between indefiniteness approaches used in the district courts and before the [PTAB] in AIA post-grant proceedings.” Id. at 5. Notably, however, the USPTO’s memorandum does not affect the USPTO’s approach to indefiniteness outside of the AIA post-grant proceeding context. Memorandum at 1. But substitute claims under any proceeding may still be challenged as indefinite. Id. at 2 n.2.