Guest Post by Profs. Masur & Ouellette: Public Use, Sales, and Public Disclosure Under the AIA

Guest post by Professors Jonathan S. Masur (UChicago Law) and Lisa Larrimore Ouellette (Stanford Law).

Imagine the following hypothetical scenarios:

Scenario 1:

• January 1, 2026: Aleida invents a new widget and gives it without a confidentiality restriction to Charlise, who uses the invention (thus creating a public use) but in a non-enabling way.
• February 1, 2026: Bruno independently invents the same widget and files for a patent on it.
• March 1, 2026: Aleida files for a patent on the widget.

Scenario 2:

• January 1, 2026: Aleida invents a new widget and offers the widget for sale to Charlise, but without any enabling disclosure. Charlise accepts the offer.
• February 1, 2026: Bruno independently invents the same widget and files for a patent on it.
• March 1, 2026: Aleida delivers the widget to Charlise and files for a patent on it.

Who do you think should receive the patent in each of these two scenarios? Maybe you think it should be Aleida in both cases, or Bruno in both cases, or Aleida in one and Bruno in the other. Regardless, we suspect that you don’t think the answer is that neither of them should receive a patent in either scenario. After all, in each scenario, both independent inventors filed patent applications less than one year after any plausible prior art. Surely someone qualifies for a patent under the America Invents Act (AIA). And yet if Federal Circuit caselaw continues on its current path, the answer might turn out to be that neither party can obtain a patent in either scenario. Let us explain.

From Sanho to NCS Multistage: What counts as a public disclosure?

Can an inventor make an invention available for public use, yet fail to “publicly disclose” it for purposes of the AIA prior art grace period? The Federal Circuit’s recent decision in NCS Multistage v. Nine Energy Service, No. 25-1000 (Fed. Cir. Sept. 14, 2026), suggests that the answer may be yes. As Dennis Crouch summarized, the court held that “a private sale does not constitute a public disclosure, even where the goods are actually delivered to the buyer without any confidentiality restriction.” This decision raises the possibility that when an inventor puts an invention into public use, it could block anyone else from patenting without protecting the inventor’s own right to a patent.

Until recently, there was zero Federal Circuit caselaw on what it meant to publicly disclose an invention. That changed in 2024, when the Federal Circuit decided Sanho v. Kaijet Technology International, 108 F.4th 1376 (Fed. Cir. 2024). In a thoughtful and well-reasoned opinion, the court held that the sale of an invention—without more—was not a public disclosure under § 102(b)(2)(B), despite the fact that it was a prior art disclosure under § 102(a)(1). As the court explained, “Section 102(b)(2)(B) thus works to protect inventors who share their inventions with the public from later disclosures made by others.” Sanho, 108 F.4th at 1382. A sale, standing by itself, does not do this; it merely allows the inventor to commercially exploit the invention. This understanding of § 102(b)(2)(B) aligns with our argument in Real-World Prior Art, 76 Stan. L. Rev. 703 (2024), that sales should be understood differently than other types of prior art because they implicate different animating principles of patent law.

But the Sanho opinion went further. The court rejected the patentee’s argument that any public use was necessarily a public disclosure under § 102(b)(2)(B), stating that “there is no requirement that such a public use necessarily ‘publicly disclose[s]’ the invention.” Sanho, 108 F.4th at 1383. The court did not need to reach this issue: nothing in the opinion suggests that the invention had actually been put into public use. It is also unclear that the Sanho court was even referring to traditional public use—i.e., use by a member of the public (someone not under a duty of confidentiality to the inventor)—as opposed to “commercial public use,” “an inventor’s commercial exploitation of [a] secret process.” Sanho, 108 F.4th at 1384.

Moreover, the Sanho court suggested that it matters “whether the public has learned the relevant aspects of the invention.” Sanho, 108 F.4th at 1384. That implied that the court understood “publicly disclosed” to incorporate something like an enablement requirement: an invention was only publicly disclosed if enabling information had reached the public. If that were the rule, then any public use that did not disclose the invention in an enabling fashion—as in classic cases like Egbert v. Lippmann, 104 U.S. 333 (1881), and Lockwood v. American Airlines, 107 F.3d 1565 (Fed. Cir. 1997)—would not count as a public disclosure.

In NCS Multistage v. Nine Energy Service, the Federal Circuit went further down this path. As Dennis’s excellent post explains, the patentee (NCS) says it had not only sold the invention to a member of the public (Tundra, which had “no non-disclosure agreement” with NCS), it had actually delivered dozens of copies of the invention to Tundra. (The court notes that technical documents provided by NCS were marked confidential, but the potential prior art is the real-world product, not the accompanying documents.) Despite this receipt by a member of the public, the court held that this could not constitute a public disclosure under § 102(b)(1)(B) because “there is no evidence that [the inventions] were widely distributed or placed where the public could examine them.” Rather, the inventions were delivered in a “sealed black tube” so that members of the public could not “determine the ‘relevant aspects of the invention,’” and “there was no teaching of the relevant aspects of the invention.” NCS, slip op. at 22–23.

The NCS court does not explicitly say that Tundra put the invention into public use, and it does not announce a formal enablement test. We thus would not describe the opinion as squarely holding that traditional public use—use by someone not under an obligation of confidentiality to the inventor—does not constitute a public disclosure unless it is enabling. But its insistence on teaching the invention’s relevant aspects points in that direction.

Public access does not always require an enabling disclosure

The suggestion that a prior art “public use” under § 102(a)(1) might not count as having “publicly disclosed” the invention under § 102(b)(1)(B) strikes us as a peculiar and perhaps misguided result for two reasons.

First, in a case of use by a member of the public (as opposed to commercialization by the inventor), some member of the public has gained unfettered access to the invention and is using it to their own benefit. The invention has unquestionably been “made available to the public.” NCS, slip op. at 21; Sanho, 108 F.4th at 1382. Yes, in some cases the use is “confined to one person,” Egbert, 104 U.S. at 336, and the public may not be able to see the invention’s “inner workings,” Lockwood, 107 F.3d at 1570. But if that is enough under blackletter public use doctrine to constitute prior art against the world under § 102(a)(1), it’s not clear why it shouldn’t be enough for a “public disclosure.”

To be sure, there are some “public use” cases that have something like an enablement requirement, which is perhaps what the NCS court had in mind. As we explained in Real-World Prior Art, a small line of cases suggests a second route to public use: use by the inventor under non-secret conditions that teach the public how the invention works, such as an enabling public demonstration. A demonstration in which the public only observes the invention is more analogous to a conference presentation than to traditional public use: it benefits the public only to the extent it teaches how the invention works. An enablement requirement thus makes sense for evaluating whether this kind of use has “publicly disclosed” the invention under § 102(b)(1)(B). But that same enablement requirement also determines whether it is “public use” prior art under § 102(a)(1) at all. Whether a use is public use prior art and whether it has publicly disclosed the invention should rise and fall together.

Second, if NCS is read to incorporate an enablement requirement, neither Aleida nor Bruno could obtain a patent in Scenario 1 above. Charlise’s public use is prior art against Bruno under § 102(a)(1). Once published, Bruno’s patent filing is prior art against Aleida under § 102(a)(2). And Aleida would not have a safe harbor under § 102(b)(2)(B) because Charlise’s public use was not enabling. This outcome would seem to contradict the intended structure of the AIA, in which the first party to publicly disclose the invention is entitled to a patent if they file within one year of that disclosure.

The mirror-image question: Can a sale that is not a public disclosure be prior art against third parties?

The NCS problem is the mirror image of the question we discussed in a Patently-O post last year: If an inventor’s private sale—one that does not put the invention into public use or lead to other prior art—does not “publicly disclose” the invention (as the Federal Circuit held in Sanho), why should it block an independent third-party inventor from patenting? If a private sale created prior art against the world (rather than only against the seller), it too could block anyone else from patenting without protecting the inventor’s right to a patent.

The principle we suggested for public uses also applies to sales: whether an activity counts as prior art against third parties and whether it publicly discloses the invention should rise and fall together. A private sale is not a public disclosure (as Sanho correctly held), so a private sale should not be prior art against anyone but the seller. In Real-World Prior Art and our prior post, we explain in detail why the best understanding of the on-sale bar is that it is party-specific, including that its central purpose (preventing an inventor from extending commercial exclusivity beyond the patent term) is not implicated by third-party sales.

This issue is implicated in Scenario 2. Recall that in Scenario 2, Aleida made a sale to Charlise (with no delivery, public use, or enabling disclosure before Bruno filed), then Bruno filed for a patent, and then Aleida filed for a patent. If Aleida’s sale were prior art against the world rather than being party-specific, we would again have a situation in which neither Aleida nor Bruno could obtain a patent. Aleida’s sale would be prior art against Bruno under § 102(a)(1). Bruno’s patent filing is prior art against Aleida under § 102(a)(2). And Aleida does not have a safe harbor under § 102(b)(2)(B) because her sale did not publicly disclose the invention (per Sanho). Again, this seems contrary to the AIA’s intent.

Cellulose v. SC Marketing: Will the Federal Circuit be able to sort these problems out?

The pending appeal in Cellulose Material Solutions v. SC Marketing Group, No. 25-2000, which will be argued on December 8, offers an opportunity for the Federal Circuit to begin untangling these issues. We think the answers should turn on a distinction we developed in Real-World Prior Art: commercial exploitation by an inventor and public access to an invention serve distinct functions in patent law, and keeping those functions separate helps make sense of the prior art rules and their exceptions.

As explained in our prior post and amicus brief, the district court in Cellulose held on summary judgment that a private third-party sale in April 2016 by defendant Thermal Shipping Solutions (TSS) (analogous to Aleida in Scenario 2 above) invalidated a later patent by plaintiff Cellulose (analogous to Bruno). Whether the product was delivered before Cellulose filed is disputed, which the district court said was irrelevant because a commercial offer for sale suffices. But if, as we suggest, a sale only creates prior art against third parties when it leads to public use or another form of public access, the delivery date could matter. Cellulose’s reply brief endorses our view of the on-sale bar.

Cellulose also argues that it “publicly disclosed” the invention before the April 2016 sale by non-confidentially sharing samples of the invention with TSS customers (i.e., members of the public). It contends that examining a shared sample “would readily reveal the nature of its construction,” which suggests that the samples might satisfy any implied enablement requirement. The district court rejected this argument under Sanho, even though Sanho was about a private sale that had not yet led to a public use or other prior art. NCS Multistage has made it even more essential for the Federal Circuit to determine whether that is in fact the right way to understand the AIA.

If the Federal Circuit panel chooses to reverse on this basis (or on Cellulose’s separate argument about disputed factual issues), it would not need to address the third-party sale issue. We think it would be helpful, however, for the court to begin untangling its conflicting precedent in this area.

As summarized in our brief, courts have long distinguished between a third party’s private commercial exploitation, which does not invalidate another inventor’s later-filed patent, and the inventor’s own commercial exploitation, which does. This dates to canonical cases such as Gillman v. Stern, 114 F.2d 28 (2d Cir. 1940), and Gore v. Garlock, 721 F.2d 1540 (Fed. Cir. 1983), as well as the more recent decision in Poly-America v. GSE Lining Technology, 383 F.3d 1303 (Fed. Cir. 2004). On a number of other occasions, the Federal Circuit has stated that third-party sales do bar independent inventors—but in all but one of those cases, the sale had created another type of prior art by putting the invention into public use or disclosing the invention to the public in an enabling way. And as patent treatise author Robert Matthews noted on our earlier post, one of these cases—J.A. LaPorte v. Norfolk Dredging, 787 F.2d 1577 (Fed. Cir. 1986)—doesn’t even present an independent third-party sale because the seller obtained the invention from the first-party inventor, who assented to the sale. These cases could thus be distinguished on their facts.

The one case in which the Federal Circuit said it was invalidating a patent based on a third-party sale that did not involve public use or disclosure is Evans Cooling Systems v. General Motors, 125 F.3d 1448 (Fed. Cir. 1997). In that case, the court held that a GM dealer’s contract to sell a Corvette invalidated a later patent by Evans, and there is no indication that the car had been delivered or the invention otherwise made public before the critical date. But like J.A. LaPorte, Evans doesn’t present a true third-party sale stemming from an independent inventor. The patentee, Evans, alleged that GM had misappropriated his invention, and the court held that the on-sale bar still applied. As in J.A. LaPorte, the court noted that the inventor knew of the alleged theft when it occurred and could have protected his rights by filing within a year.

It thus appears that while the Federal Circuit has repeatedly said that third-party sales bar independent inventors, none of these cases have squarely presented a truly independent and private sale—that is, one that stems from an independent inventor and does not create another type of prior art (by placing the invention in public use or creating an enabling disclosure). In contrast, the only cases that have directly presented this issue have held that commercial exploitation by a third party does not bar an independent inventor. See Gore, 721 F.2d at 1550; Poly-America, 383 F.3d at 1308–09.

In our view, the Federal Circuit’s 1983 decision in Gore v. Garlock on first- versus third-party commercial exploitation reached the right result. The court should clarify that this reasoning applies to any form of commercial exploitation that does not give the public access to the invention (including sale of a claimed product, or sale of a product produced by a claimed process, or sale of services that will use a claimed product or process), and that these issues fit better under the on-sale bar than the public-use bar. Helsinn v. Teva, 586 U.S. 123 (2019), which TSS relies on in response to our amicus brief, does not suggest otherwise: it involved a sale by the patentee, and the pre-AIA caselaw that it preserved includes Gore v. Garlock. Indeed, in a recent discussion of why amendments were not “intended to alter Section 102’s on-sale bar,” the Federal Circuit explicitly noted Gore’s distinction, “relevant to the on-sale bar,” between “the inventor’s own commercialization and that by a third-party.” Celanese v. ITC, 111 F.4th 1338, 1348 (Fed. Cir. 2024).

The Federal Circuit need not adopt our preferred labels to clarify this muddled body of caselaw. For example, it could continue to hold that sales constitute prior art against parties other than the seller—but only after the invention has been delivered or otherwise made accessible to the purchaser. The relevant date would then be when the access occurs, often on delivery, rather than the date of a private offer. This approach could also reach an informative product delivered without restriction even if the purchaser leaves it unused. We still favor maintaining a crisp distinction between sales—as prior art only against the seller—and public uses—as prior art against everyone—to align these rules with their purposes. But either approach would require courts to ask what the transaction actually made public, and when. And whatever labels the court uses, the same principle should resolve both issues discussed in this post: an activity that gives the public access to an invention should both bar others and protect the inventor responsible for it, while commercial exploitation that has not yet led to public access should bar only the seller.

Should Aleida or Bruno receive a patent?

Returning to our original scenarios: In our view, Aleida should obtain the patent in Scenario 1. She allowed a member of the public to use the invention without restriction, and thus “publicly disclosed” it, which both bars Bruno and gives Aleida the § 102(b)(2)(B) safe harbor against his filing. Bruno should obtain the patent in Scenario 2. Aleida’s sale isn’t prior art against independent third-party inventor Bruno, and because it didn’t publicly disclose the invention, it doesn’t give her a safe harbor against Bruno’s earlier filing. But at the very least, we think someone should get the patent in each scenario, and we hope the Federal Circuit resolves the confusion in this area.

As we noted before, we have no financial interest in the outcome; we would simply like to see the law clarified in a sensible way!