United States Court of Appeals 

for the Federal Circuit ______________________

REGENTS OF THE UNIVERSITY OF MINNESOTA,

Appellant

v.

LSI CORPORATION, AVAGO TECHNOLOGIES U.S.

INC.,

Appellees

GILEAD SCIENCES, INC.

Intervenor

______________________

2018-1559

______________________

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2017-

01068.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

REGENTS OF THE UNIVERSITY OF MINNESOTA,

Appellant

v.

ERICSSON INC., TELEFONAKTIEBOLAGET LM 

ERICSSON,

Appellees
2 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

GILEAD SCIENCES, INC.

Intervenor

______________________

2018-1560, 2018-1561, 2018-1562, 2018-1563, 2018-1564, 

2018-1565

______________________

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2017-

01186, IPR2017-01197, IPR2017-01200, IPR2017-01213, 

IPR2017-01214, IPR2017-01219.

______________________

Decided: June 14, 2019

______________________

MICHAEL A. ALBERT, Wolf, Greenfield & Sacks, PC, 

Boston, MA, argued for appellant. Also represented by 

STUART DUNCAN SMITH, RICHARD GIUNTA, GERALD B.

HRYCYSZYN, CHARLES T. STEENBURG. 

 KRISTOPHER L. REED, Kilpatrick Townsend & Stockton 

LLP, Denver, CO, argued for all appellees. Appellees LSI 

Corporation, Avago Technologies U.S. Inc. also represented 

by EDWARD JOHN MAYLE, DAVID E. SIPIORA. 

 MARK S. DAVIES, Orrick, Herrington & Sutcliffe LLP, 

Washington, DC, for appellees Ericsson Inc., Telefonaktiebolaget LM Ericsson. Also represented by EASHA ANAND,

WILL MELEHANI, San Francisco, CA; EDMUND HIRSCHFELD, 

New York, NY; DEBRA JANECE MCCOMAS, Haynes & Boone, 

LLP, Dallas, TX; J. ANDREW LOWES, Richardson, TX.

 ADAM MORTARA, Bartlit Beck LLP, Chicago, IL, argued 

for intervenor. Also represented by NEVIN M. GEWERTZ; 

MEG E. FASULO, Denver, CO. 

 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 3

 COURTNEY DIXON, Appellate Staff, Civil Division, 

United States Department of Justice, Washington, DC, argued for amicus curiae United States. Also represented by 

MARK R. FREEMAN, ALISA BETH KLEIN, MARK B. STERN, 

JOSEPH H. HUNT. 

 JOSHUA STEPHEN JOHNSON, Vinson & Elkins LLP, 

Washington, DC, for amicus curiae Association of Public 

and Land-grant Universities. Also represented by JOHN 

PATRICK ELWOOD. 

 MICHAEL W. SHORE, Shore Chan DePumpo LLP, Dallas, TX, for amici curiae STC.UNM, The Board of Trustees 

of Purdue University, The Board of Trustees of Indiana 

University. Also represented by ALFONSO CHAN, RUSSELL 

J. DEPALMA; ANDREW M. HOWARD, Howard & Spaniol, 

PLLC, Dallas, TX. 

 THOMAS MOLNAR FISHER, Solicitor General, Indiana 

Office of Attorney General, Indianapolis, IN, for amici curiae State of Indiana, State of Texas, State of Hawaii, State 

of Illinois, State of Massachusetts, State of Michigan, State 

of Minnesota, State of Mississippi, State of New Jersey, 

State of Ohio, State of Rhode Island, State of South Carolina, State of Utah, State of Virginia. Also represented by 

JASON R. LAFOND, Office of the Attorney General of Texas, 

Austin, TX. 

 JOHN THORNE, Kellogg, Hansen, Todd, Figel & Frederick, P.L.L.C., Washington, DC, for amici curiae Computer 

& Communications Industry Association, High Tech Inventors Alliance, The Internet Association, L Brands, Inc., 

Newegg Inc., Red Hat, Inc., SAP America, Inc., SAS Institute Inc., The Software & Information Industry Association, Symmetry LLC, Xilinx. Also represented by DANIEL 

SIMON GUARNERA, ARIELA M. MIGDAL, GREGORY G.

RAPAWY.
4 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

 JOEL THAYER, Washington, DC, for amicus curiae ACT 

The App Association. 

 ANNA-ROSE MATHIESON, California Appellate Law 

Group, San Francisco, CA, for amicus curiae America's 

Health Insurance Plans. 

 MARK A. LEMLEY, Durie Tangri LLP, San Francisco, 

CA, for amici curiae Jeremy W. Bock, Michael A. Carrier, 

Andrew Chin, Brian L. Frye, Shubha Ghosh, Yaniv Heled, 

Mark A. Lemley, Yvette Joy Liebesman, Brian J. Love, Susan Barbieri Montgomery, Tejas N. Narechania, Tyler T. 

Ochoa, Arti K. Rai. 

 ______________________

Before DYK, WALLACH, and HUGHES, Circuit Judges.

Opinion for the court by Circuit Judge DYK, in which 

WALLACH and HUGHES, Circuit Judges, join.

Additional views by Circuit Judges DYK, WALLACH, and 

HUGHES.

DYK, Circuit Judge.

The Regents of the University of Minnesota (“UMN”) 

appeals from decisions by the United States Patent and 

Trademark Office (“USPTO”) Patent Trial and Appeal 

Board (“Board”) declining to dismiss petitions for inter 

partes review (“IPR”). The petitions were alleged to be improper because states supposedly enjoy sovereign immunity in IPR proceedings. We conclude that state sovereign 

immunity does not apply to these proceedings, and therefore we affirm. 

BACKGROUND

The University of Minnesota is an arm of the state of 

Minnesota and is one of the largest public research institutions in the country. It pursues patent protection for inventions resulting from its research and is the owner of U.S. 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 5

Patent Nos. 5,859,601 (’601 patent), 7,251,768 (’768 patent), 7,292,647 (RE45,230 patent), 8,588,317 (’317 patent),

8,718,185 (’185 patent), and 8,774,309 (’309 patent). The 

patents were assigned to UMN at the outset of prosecution, 

and they were issued between January 12, 1999, and July 

8, 2014. These patents cover two distinct technologies.

Appellee LSI Corp. designs and supplies semiconductors; it is alleged to infringe UMN’s ’601 patent, which 

claims particular types of “read channel” chips. Appellee 

Ericsson Inc. is a telecommunications company. Its customers’ use of Ericsson’s products was alleged to infringe 

UMN’s ’768, RE45,230, ’317, ’185, and ’309 patents. These 

patents claim technology used for 4G LTE networks.

UMN, alleging infringement of these patents, sued LSI 

and separately sued Ericsson’s customers in district court.

Ericsson intervened in the customer suits. 

After the commencement of the suits for patent infringement, LSI and Ericsson separately petitioned for IPR 

seeking a determination of unpatentability of the challenged claims on grounds of anticipation and obviousness. 

See LSI Corp. v. Regents of the Univ. of Minn., No. 

IPR2017-01068, Paper 1 (P.T.A.B. Mar. 10, 2017); Ericsson 

Inc. v. Regents of the Univ. of Minn., Nos. IPR2017-01186, 

Paper 1 (P.T.A.B. Mar. 28, 2017); IPR2017-01197, Paper 1 

(P.T.A.B. Mar. 29, 2017); IPR2017-01200, Paper 1 

(P.T.A.B. Mar. 30, 2017); IPR2017-01213, Paper 1 

(P.T.A.B. Mar. 30, 2017); IPR2017-01214, Paper 1 

(P.T.A.B. Mar. 30, 2017); IPR2017-01219, Paper 1

(P.T.A.B. Mar. 30, 2017).

After the petitions for IPR were filed, and before the 

USPTO decided whether to institute IPR, UMN filed a motion to dismiss in each proceeding based on state sovereign 

immunity. The USPTO convened an expanded panel, consisting of three administrative patent judges as well as the 

Chief Judge, Deputy Chief Judge, and two Vice Chief 

Judges. In each proceeding, the Board concluded that state 
6 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

sovereign immunity applied to IPR proceedings but that 

UMN waived its immunity by filing suit against petitioners 

in district court.1 A concurrence to each of the Board decisions concluded that sovereign immunity was not implicated in part because “[a]t its core, inter partes review is a 

circumscribed in rem proceeding, in which the Patent Office exercises jurisdiction over the patent challenged, rather than the parties named.” J.A. 13; J.A. 33.

UMN appealed the Board’s decisions, and the cases 

have been consolidated on appeal. Gilead Sciences, Inc., 

facing the same issue for its own IPR petitions, sought 

leave to intervene, which was granted. Regents of the Univ. 

of Minn. v. LSI Corp., Appeal No. 2018-1559 (Fed. Cir. Apr.

19, 2018), ECF No. 35. We have jurisdiction under 

28 U.S.C. § 1295(a)(4)(A).2

 

1 The Board’s order denying UMN’s motion to dismiss is at LSI Corp. v. Regents of the University of Minnesota, No. IPR2017-01068, Paper 19 (P.T.A.B. Dec. 19, 

2017), which is identical in relevant part to the Board’s order in Ericsson Inc. v. Regents of the University of Minnesota, Nos. IPR2017-01186, Paper 14; IPR2017-01197, 

Paper 14; IPR2017-01200, Paper 16; IPR2017-01213, Paper 14; IPR2017-01214, Paper 14; IPR2017-01219, Paper 

15 (P.T.A.B. Dec. 19, 2017). 

2 Appellee LSI argues that UMN’s appeal is not ripe 

because any harm to UMN would not occur unless and until the Board instituted IPR, which may or may not occur.

(The USPTO and the other parties to this appeal do not 

challenge our jurisdiction). It is well-established that decisions denying sovereign immunity are appealable as collateral orders, and the “ultimate justification is the 

importance of ensuring that the States’ dignitary interests 

can be fully vindicated.” P.R. Aqueduct & Sewer Auth. v. 

Metcalf & Eddy, Inc., 506 U.S. 139, 146–47 (1993) (citing 

Mitchell v. Forsyth, 472 U.S. 511, 527–29 & n.10 (1985)); 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 7

While this appeal was pending, this court decided 

Saint Regis Mohawk Tribe v. Mylan Pharmaceuticals Inc., 

896 F.3d 1322 (Fed. Cir. 2018), holding that IPR proceedings were not barred by tribal sovereign immunity. A petition for certiorari was filed in that case, and the petition 

was denied, 139 S. Ct. 1547.

DISCUSSION

I. Post-Issuance Administrative Proceedings3

Addressing the issue of state sovereign immunity requires a detailed understanding of the history of IPR proceedings and the reasons that Congress created such 

proceedings. 

The USPTO is an agency within the Department of 

Commerce and is “responsible for the granting and issuing 

of patents.” 35 U.S.C. §§ 1, 2. Almost every year the number of submitted patent applications has increased, from 

approximately 100,000 in 1980 to nearly 650,000 in 2018. 

U.S. Patent & Trademark Office, U.S. Patent Statistics, 

Calendar Years 1963-2015, https://www.uspto.gov/web/

 

see Chehazeh v. Attorney Gen. of U.S., 666 F.3d 118, 135–

36 (3d Cir. 2012) (collecting cases); see also Mohawk Indus., 

Inc. v. Carpenter, 558 U.S. 100, 110 (2009). We see no material difference between a decision made after institution 

of IPR, as in Saint Regis Mohawk Tribe v. Mylan Pharmaceuticals Inc., 896 F.3d 1322, 1325 (Fed. Cir. 2018), and a 

decision made before institution, as in this case. Given 

UMN’s alleged dignitary interests in avoiding IPR, the 

“purely legal” issue of whether sovereign immunity bars 

IPR for state-owned patents is ripe for review. See Abbott 

Labs. v. Gardner, 387 U.S. 136, 149 (1967), abrogated on 

other ground by Califano v. Sanders, 430 U.S. 99, 105 

(1977). 

3 This history is discussed in the majority and concurrence in Saint Regis.
8 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

offices/ac/ido/oeip/taf/us_stat.pdf; U.S. Patent & Trademark Office, FY 2018 Performance & Accountability Report

179 tbl.2 (2018) [hereinafter FY2 2018 P&A Rpt.], 

https://www.uspto.gov/sites/default/files/documents/

USPTOFY18PAR.pdf. This has led to a steady backlog of 

applications, and the USPTO now issues approximately 

300,000 patents each year. FY 2018 P&A Rpt., at 180 tbl.3; 

id. at 181 tbl.6. To perform its duty to examine and issue 

patents, the USPTO relies on a corps of approximately

8,000 patent examiners who are charged with determining 

whether an applicant is entitled to a patent for a claimed 

invention. Id. at 205 tbl.28. Although essential to the examination process, the agency struggles to attract and retain examiners able to perform sufficiently thorough prior 

art searches and make a patentability determination.4

Given the large number of patent applications, patent 

examiners only receive roughly 22 hours to review each application, which 70% of examiners have reported as insufficient time. U.S. Gov’t Accountability Office, GAO-16-490, 

Patent Office Should Define Quality, Reassess Incentives, 

and Improve Clarity 10, 25–26 (2016) [hereinafter Quality, 

Incentives, & Clarity]. In those 22 hours, examiners must 

ensure not only that technical formalities are met, but also 

that the statutory requirements for patentability, such as 

novelty and non-obviousness, are met. For this determination, the USPTO relies on the examiner’s prior art searching, aided by prior art the applicant identifies.

For many years, until 2000, there was virtually no public input in the initial examination process since patent applications were not published. Beginning in 2000, patent 

 

4 See U.S. Gov’t Accountability Office, GAO-16-479, 

Patent Office Should Strengthen Search Capabilities and 

Better Monitor Examiners’ Work 28–29 & 28 n.50 (2016); 

FY 2018 P&A Rpt., at 205 tbl.28 (2018) (showing net attrition of more than 450 examiners from 2014 to 2018).
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 9

applications have been typically published 18 months after 

the earliest claimed filing date, see 35 U.S.C. § 122; 37 

C.F.R. § 1.211, and Congress has provided for some limited

public participation during the initial examination,5 see 35 

U.S.C. §§ 122(c), (e); H.R. Rep. No. 112–98, pt. I, at 48–49 

(2011); 37 C.F.R. §§ 1.290–91. Nonetheless, in light of the 

USPTO’s constrained resources and the absence of material outside input during the initial examination, it is inevitable that there are patents granted in error.6

This is not a new phenomenon. In 1980, Congress was 

concerned that this was “a situation where a limited staff 

is trying to cope with a constantly increasing workload and 

is under pressure to make speedy determinations on 

whether or not to grant patents.” S. Rep. No. 96–617, at 8 

(1980); see also Patent Reexamination: Hearing on S. 1679 

Before the Comm. on the Judiciary, 96th Cong. 3 (1980) 

 

5 After a patent application is published, a third 

party may file a pre-issuance submission, which includes 

either a patent application, published patent application, 

or other printed publication and, after 2011, a concise 

statement as to the relevance of the submitted prior art to 

the patentability of the claimed invention. 35 U.S.C. 

§ 122(e); 37 C.F.R. § 1.290.

6 See Quality, Incentives, & Clarity, at 25 

(“[E]xaminers’ time pressures are one of the central challenges for patent quality.”); see also Michael D. Frakes & 

Melissa F. Wasserman, Does the U.S. Patent and Trademark Office Grant Too Many Bad Patents?: Evidence from 

a Quasi-Experiment, 67 Stan. L. Rev. 613, 652–53 (2015) 

(finding increased patent grant rates correlated with increased resource strain on the USPTO); Shawn P. Miller, 

Where’s the Innovation: An Analysis of the Quantity and 

Qualities of Anticipated and Obvious Patents, 18 Va. J.L. & 

Tech. 1, 45 (2013) (estimating that 28% of issued patents 

would be invalidated as anticipated or obvious).
10 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

(statement of Sen. Bayh) (characterizing the USPTO as “an 

understaffed and overworked office trying to handle an 

ever increasing workload”); Industrial Innovation and Patent and Copyright Law Amendments: Hearing on H.R. 

6033, H.R. 6934, H.R. 3806, H.R. 2414 Before the Subcomm. on Courts, Civil Liberties & the Admin. of Justice of 

the H. Comm. on the Judiciary, 96th Cong. 580–81 (1981) 

(statement of Sidney A. Diamond, Commissioner of Patents 

and Trademarks). Congress’ solution was to provide for 

reexamination of the original patent grant.

In general, until 1980 the only way the original patent 

grant could be challenged was in patent litigation in district court by a declaratory judgment action or as a defense 

in a patent infringement action, both of which could be extremely expensive and both of which generally were not 

available until a claim of infringement was asserted by the 

patent owner. See Patlex Corp. v. Mossinghoff, 758 F.2d 

594, 601–02 (Fed. Cir. 1985); S. Rep. 96–617, at 9–10 (testimony of Sidney A. Diamond, Commissioner of Patents 

and Trademarks).7 In this respect, the United States’ patent system diverged from its English origins, which had 

for centuries recognized the executive’s ability to reconsider a prior patent grant.8 In 18th-century England, 

 

7 There were earlier post-grant administrative proceedings to determine who was the proper owner of a patented invention (i.e., an interference proceeding), see, e.g., 

Morgan v. Drake, 36 F.2d 511 (C.C.P.A. 1929), and to 

reevaluate the patentability of a patented invention based 

on an application by the patent owner (i.e., a reissue proceeding), see Fresenius USA, Inc. v. Baxter Int’l, Inc., 721 

F.3d 1330, 1336–40 (Fed. Cir. 2013) (discussing history).

8 See In re Bilski, 545 F.3d 943, 966–76 (Fed. Cir. 

2008) (en banc) (Dyk, J., concurring) (discussing the relationship between the U.S. patent law and the English common law); Mark A. Lemley, Why Do Juries Decide If 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 11

parties could challenge the validity of a patent by petitioning the government via the Privy Council to revoke the

public franchise. Oil States Energy Servs., LLC v. Green’s 

Energy Grp., LLC, 138 S. Ct. 1365, 1376–78 (2018). “The 

Privy Council was a prominent feature of the English system,” and “[b]ased on the practice of the Privy Council, it 

was well understood at the founding that a patent system 

could include a practice of granting patents subject to potential cancellation in the executive proceeding.” Id. at 

1377. 

In 1980, Congress for the first time enacted post-grant 

review provisions allowing a challenge to the validity of an

issued patent in an ex parte reexamination process.9 Act of 

Dec. 12, 1980, Pub. L. No. 96–517, 94 Stat. 3015 (1980). In 

these proceedings, Congress sought to enlist the assistance 

 

Patents Are Valid?, 99 Va. L. Rev. 1673, 1691–704 (2013) 

[hereinafter Why Do Juries Decide?] (discussing the divergence of early American and English patent practice).

9 Prior to 1836, Congress had authorized suit for 

scire facias to invalidate a patent where the suit, though 

brought by a private party, was under the control of the 

United States. In the Patent Act of 1836, Congress repealed that provision, but the Supreme Court concluded 

that the statutory change did not remove the United 

States’ ability to sue in equity to invalidate a patent, at 

least where there had been fraud on the patent office. See

United States v. Am. Bell. Tel. Co., 128 U.S. 315, 371–73 

(1888) (“[Such a suit by the United States] is so widely different, so much more beneficial, and is pursued under circumstances so much more likely to secure complete justice, 

than any defense which can be made by an individual infringer, that it is impossible to suppose that congress, in 

granting this right to the individual, intended to supersede 

or take away the more enlarged remedy of the government.”); Why Do Juries Decide, supra n.8, at 1695–97.
12 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

of third parties to identify relevant prior art so as to address the lack of public trust and confidence in the patent 

system’s ability to weed out bad patents in initial ex parte 

examination.10 As the USPTO Commissioner explained

during consideration of the 1980 legislation,

The main reason [the new procedure of] reexamination is needed is because members of the public 

interested in the validity of a patent are sometimes 

able to find pertinent prior patents and printed 

publications not known or available to the 

PTO . . . .

The patent owner’s competitors will devote great 

effort and expense to invalidating a patent that affects their businesses. They can afford to look for 

documentary evidence of unpatentability in library 

collections, technical journals and other sources 

not within the PTO’s search file. Because of budgetary and time constraints, the examiner’s search 

seldom extends beyond the PTO’s 22 million document collection.

Industrial Innovation and Patent and Copyright Law 

Amendments: Hearing on H.R. 6033, H.R. 6934, H.R. 3806, 

H.R. 2414 Before the Subcomm. on Courts, Civil Liberties 

& the Admin. of Justice of the H. Comm. on the Judiciary, 

96th Cong. 576 (1981) (statement of Sidney A. Diamond, 

Commissioner of Patents and Trademarks). Not only would

the USPTO benefit from greater public participation in

post-grant proceedings, but the proceedings also had new 

 

10 Mark D. Janis, Rethinking Reexamination: Toward 

a Viable Administrative Revocation System for U.S. Patent 

Law, 11 Harv. J.L. & Tech. 1, 9–10 (1997); see S. Rep. No. 

96–617, at 2–3, 14 (1980); H.R. Rep. No. 96–1307, pt. 1, at 

3 (1980) (expressing concern as to the lack of confidence in 

the patent system).
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 13

procedures that would allow the agency to focus its resources on reevaluating those patents of particular concern 

to the public.11

Thus, “[t]he reexamination statute enabled the PTO to 

recover administrative jurisdiction over an issued patent 

in order to remedy any defects in the examination which 

that agency had initially conducted and which led to the 

grant of the patent.” Patlex, 758 F.2d at 601. Under the

reexamination procedures, if the USPTO learned of prior 

art that raised “a substantial new question of patentability” it could institute an ex parte reexamination. 35 U.S.C. 

§ 303.

However, ex parte reexaminations did not solve the 

agency’s problems. Once instituted, ex parte reexamination largely followed the same process as the initial examination, without further third-party input. S. Rep. No. 110–

259, at 18–19 (2008). It “follow[ed] essentially the same inquisitorial process between patent owner and examiner as 

the initial Patent Office examination.” SAS Inst., Inc. v. 

Iancu, 138 S. Ct. 1348, 1353 (2018) (citing 35 U.S.C. § 305).

In this respect, it was “meaningfully different” from the inter partes reexamination and IPR proceedings that Congress adopted thereafter. Return Mail, Inc. v U.S. Postal 

Serv., No. 17-1594, slip op. at 14 (June 10, 2019).

In 1999, seeking to enhance the process, Congress enacted provisions for the inter partes reexamination 

 

11 See Kimberly A. Moore, Worthless Patents, 20 

Berkeley Tech. L.J. 1521, 1521–22, 1530–31 (2005) (noting 

that only a small fraction of issued patents are ever asserted and that, in the sample of patents studied, more 

than half of all the issued patents expired for failure to pay 

maintenance fees); Mark A. Lemley, Rational Ignorance at 

the Patent Office, 95 Nw. U. L. Rev. 1495, 1497, 1501–08 

(2001) (same).
14 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

proceedings, in order to increase third party participation. 

Act of Nov. 29, 1999, Pub. L. No. 106–113, 113 Stat. 1501 

(1999); see H.R. Rep. 106–464, at 133 (1999). 

Similar to ex parte reexamination, the inter partes 

reexamination process began with a third-party request for 

reexamination based on prior art, and if the prior art raised 

a substantial new question of patentability, the USPTO 

would grant the request and proceed with reexamination. 

35 U.S.C. § 312 (2002). However, significantly, unlike ex 

parte reexamination, inter partes reexamination allowed

the third-party requestor to participate throughout the 

proceeding. “Each time that the patent owner file[d] a response to an action on the merits from the [USPTO], the 

third-party requester shall have one opportunity to file 

written comments addressing issues raised by the action of 

the Office or the patent owner’s response thereto.” Id.

§ 314. The third party could also appeal to the Board of Patent Appeals and Interferences if the examiner found the 

claims to be not unpatentable. “The participation by third 

parties [was] considered vital” to the goal of “improving patent quality and validity” because “in many circumstances 

they [would] have the most relevant prior art available and 

incentive to seek to invalidate an allegedly defective patent.” H.R. Rep. 107–120, at 4 (2001). After 1999, Congress 

continued to tweak ex parte and inter partes proceedings, 

but they were less widely used than Congress had hoped 

and had features that made them “troublesomely inefficient and ineffective as a truly viable alternative for resolving questions of patent validity.” S. Rep. No. 110–259, at 

19 (2008).12

 

12 For example, until 2002, a person requesting reexamination of a patent could not solely rely on prior art that 

the USPTO had already considered. See Pub. L. 107–273, 

§ 13105, 116 Stat. 1758, 1900 (2002). Another example of 

the deficiency of these proceedings was that inter partes 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 15

In 2011, Congress enacted the Leahy-Smith America 

Invents Act (“AIA”), Pub. L. No. 112–29, 125 Stat. 284

(2011), to “improve patent quality and limit unnecessary 

and counterproductive litigation costs.” H.R. Rep. 112–98, 

pt. I, at 40 (2011). Congress replaced inter partes reexamination with new post-grant review procedures, including 

IPR, covered business method review, and post-grant review, while retaining ex parte reexamination. IPR in particular was designed to improve on the inter partes 

reexamination process, and “[a]lthough Congress changed 

the name from ‘reexamination’ to ‘review,’ nothing convinces us that, in doing so, Congress wanted to change its

basic purposes, namely to reexamine an earlier agency decision.” Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 

2137, 2144 (2016). Just as with the prior reexamination 

procedures, IPR “allows a third party to ask the U.S. Patent and Trademark Office to reexamine the claims,” id. at 

2136, albeit with “broader participation rights,” id. at 2137. 

Before IPR can be instituted, a person must file a petition challenging the validity of one or more patent claims

under § 102 or § 103 on the basis of prior art patents or 

printed publications. 35 U.S.C. §§ 311, 312. The petition 

may be supported by declarations. 35 U.S.C. § 312(a)(3)(B). 

The petitioner need not have constitutional standing to file 

the petition or participate in IPR. Cuozzo, 136 S. Ct. at

2143–44. After filing, the petitioner has a limited ability to 

amend its petition as “the Board has determined that in 

IPR a petitioner may only make clerical or typographical 

corrections to its petition.” Saint Regis, 896 F.3d at 1328. 

The petitioner must also serve the petition on the patent 

 

reexamination took an average of three and a half years 

from initiation to a certificate issue date. See U.S. Patent 

& Trademark Office, Inter Partes Reexamination Filing 

Data (2017), https://www.uspto.gov/sites/default/files/documents/inter_parte_historical_stats_roll_up.pdf.
16 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

owner, 37 C.F.R. § 42.105, and the patent owner may, but 

need not, file a preliminary response, 35 U.S.C. § 313; 37 

C.F.R. § 42.107(a).

If the Director of the USPTO, a politically accountable 

executive officer,13 determines that the appropriately filed 

petition “shows that there is a reasonable likelihood that 

the petitioner would prevail with respect to at least 1 of the 

claims challenged in the petition,” the Director may institute IPR. 35 U.S.C. § 314(a); see 35 U.S.C. § 325(d). “The 

decision whether to institute inter partes review is committed to the Director’s discretion.” Oil States, 138 S. Ct. at 

1371. This decision is “final and nonappealable.” 35 U.S.C. 

§ 314(d); see Oil States, 138 S. Ct. at 1378 n.5 (citing 

Cuozzo, 136 S. Ct. at 2140).

Once instituted, the Board, typically a three-member 

panel of administrative patent judges, examines the validity of the asserted patent claims. A patent owner may respond to the petition after IPR is instituted, 35 U.S.C. 

§ 316(a)(8), but the petitioner bears the burden of proving 

“unpatentability by a preponderance of the evidence,” id.

§ 316(e). The procedure for reexamining the earlier decision to issue the patent by design is abbreviated compared 

to district court proceedings. See id. § 316(a)(11). During 

IPR, the patent owner and petitioner can seek discovery,

but such discovery is generally limited to “(A) the deposition of witnesses submitting affidavits or declarations; and 

(B) what is otherwise necessary in the interest of justice.” 

Id. § 316(a)(5); 37 C.F.R. § 42.51(b); see 154 Cong. Rec. 

S9988–89 (daily ed. Sept. 27, 2008) (statement of Sen. Kyl) 

(noting that “[g]iven the time deadlines imposed on these 

proceedings, it is anticipated that, regardless of the 

 

13 The Director is “appointed by the President, by and 

with the advice and consent of the Senate,” and “may be 

removed from office by the President.” 35 U.S.C. § 3(a)(1), 

(4).
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 17

standards imposed . . . PTO will be conservative in its 

grants of discovery”).14 Additionally, although the parties 

are entitled to an oral hearing, 35 U.S.C. § 316(a)(10); 37 

C.F.R. § 42.70, “[t]he hearings are short, and live testimony 

is rarely allowed.” Saint Regis, 896 F.3d at 1328 (citing Ultratec, Inc. v. CaptionCall, LLC, 872 F.3d 1267, 1270 n.2 

(Fed. Cir. 2017)).

Once instituted, the proceedings may continue without 

either the petitioner or the patent owner. The statutory 

provision states that if the petitioner stops participating, 

the Board may continue on to a final written decision. 

35 U.S.C. § 317(a). If the patent owner stops participating, 

“[t]he Board has construed its rules to allow it to continue 

review.” Saint Regis, 896 F.3d at 1328. During the proceeding the patent owner may also seek leave to amend the 

original patent claims to resolve the problem of patent eligibility, as the applicant can do in initial examination

though the proposed amendments may also be challenged 

by the petitioner. 35 U.S.C. § 316(d). 

An IPR proceeding in general must be completed 

within one year of institution. 35 U.S.C. § 316(a)(11). When 

IPR is completed, the Board issues a final written decision 

with respect to patent claims challenged by the petitioner

 

14 “[D]iscovery is limited as compared to that available in district court litigation. Limited discovery lowers the 

cost, minimizes the complexity, and shortens the period required for dispute resolution. There is a one-year statutory 

deadline for completion of inter partes review, subject to 

limited exceptions. What constitutes permissible discovery 

must be considered with that constraint in mind.” Garmin 

Int’l, Inc. v. Cuozzo Speed Techs. LLC, No. IPR2012–00001, 

2013 WL 11311697, at *3 (Paper 26) (P.T.A.B. Mar. 5, 

2013) (citations omitted) (contextualizing the Board’s interpretation of the “necessary in the interest of justice” 

prong for IPR discovery).
18 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

and any claims sought to be amended. 35 U.S.C. § 318(a). 

A party dissatisfied with the decision may then appeal to 

this court, id. § 319,15 and the Director may intervene in 

the appeal, id. § 143. After the time for appeal has expired, 

or appellate review has been exhausted, the process ultimately terminates with the USPTO issuing a certificate 

canceling, confirming, or incorporating patent claims. Id.

§ 318(b). The proceeding cannot award monetary or other 

relief against the patent owner. Following an IPR proceeding that “results in a final written decision,” statutory estoppel applies to the petitioner with respect to “any ground 

that the petitioner raised or reasonably could have raised 

during” the IPR proceeding. Id. § 315(e). The patent owner 

is estopped from obtaining “[a] claim that is not patentably 

distinct from a finally refused” claim. 37 C.F.R. 

§ 42.73(d)(3)(i).

II. State Sovereign Immunity

While admitting that both ex parte and inter partes 

reexamination did not implicate sovereign immunity,16

UMN and its supporting amici contend that states enjoy 

immunity from IPR proceedings. 

States typically enjoy immunity from lawsuits brought 

by private parties as a “fundamental aspect of the sovereignty which the States enjoyed before the ratification of 

the Constitution, and which they retain today.” Alden v. 

 

15 We have held, however, that a petitioner can only 

appeal an adverse decision by the Board if it satisfies Article III standing requirements. Consumer Watchdog v. Wis.

Alumni Research Found., 753 F.3d 1258, 1260–61 (Fed. 

Cir. 2014). 

16 “Q. Do States enjoy sovereign immunity in reexam 

proceedings? A. In an ex parte reexamination, no . . . .” 

“Q. So no sovereign immunity in inter partes reexam? 

A. . . . I would say no . . . .” Oral Arg. at 6:20–7:01.
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 19

Maine, 527 U.S. 706, 713 (1999). This is sometimes referred 

to as Eleventh Amendment immunity,17 but “the sovereign 

immunity of the States neither derives from nor is limited 

by, the terms of the Eleventh Amendment.” Id.; see Seminole Tribe of Fla. v. Florida, 517 U.S. 44, 54 (1996). “The 

preeminent purpose of state sovereign immunity is to accord States the dignity that is consistent with their status 

as sovereign entities,” while collaterally “serv[ing] the important function of shielding state treasuries.” Fed. Mar. 

Comm’n v. S.C. State Ports Auth., 535 U.S. 743, 760, 765 

(2002) (“FMC”).

This immunity applies not only to proceedings brought 

by a private party in an Article III forum but also to agency 

adjudications brought by private parties that are similar to 

court adjudications. Id. at 760. However, sovereign immunity does not apply to suits brought by the United 

States, including agency proceedings commenced by the 

United States. Id. at 752; Alden, 527 U.S. at 755 (citing 

Principality of Monaco v. Mississippi, 292 U.S. 313, 328–29 

(1934) (collecting cases)); United States v. Mississippi, 380 

U.S. 128, 140–41 (1965); United States v Texas, 143 U.S.

621, 646 (1892). The Supreme Court recognized in FMC

that sovereign immunity does not bar an agency from 

bringing an enforcement action against the state “upon its 

own initiative or upon information supplied by a private 

party.” 535 U.S. at 767–68.

UMN argues that sovereign immunity applies to IPR

proceedings where the state is the patent owner because 

they are not like suits brought by the United States but are 

entirely a dispute between a private party and the state,

 

17 “The Judicial power of the United States shall not 

be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by 

Citizens of another State, or by Citizens or Subjects of any 

Foreign State.” U.S. Const. amend. XI. 
20 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

and they share similarities with Article III proceedings 

where sovereign immunity applies. We have recently addressed the related question of whether tribal sovereign 

immunity applies to IPR proceedings in Saint Regis Mohawk Tribe v. Mylan Pharmaceuticals Inc., 896 F.3d 1322 

(Fed. Cir. 2018), cert. denied, 139 S. Ct. 1547 (2019), and 

held that it does not.

III. Saint Regis Mohawk Tribe

In Saint Regis, the Saint Regis Mohawk Tribe entered 

into an ownership agreement regarding various patents, 

which were the subject of ongoing IPR proceedings, and it 

then invoked tribal sovereign immunity as a bar to those

proceedings. Id. at 1325. We concluded that tribal sovereign immunity did not apply to IPR because the “USPTO 

[was] acting as the United States in its role as a superior 

sovereign to reconsider a prior administrative grant and 

protect the public interest in keeping patent monopolies 

‘within their legitimate scope.’” Id. at 1329 (quoting 

Cuozzo, 136 S. Ct. at 2144). 

The Supreme Court has concluded that IPR proceedings are essentially agency reconsideration of a prior patent grant. Cuozzo, 136 S. Ct. at 2144 (“[T]he purpose of the 

proceeding is not quite the same as the purpose of district 

court litigation . . . . [Instead,] the proceeding offers a second look at an earlier administrative grant of a patent.”); 

Oil States, 138 S. Ct. at 1374 (“[IPR] involves the same interests as the determination to grant a patent in the first 

instance.”). The fact that Congress has enlisted the assistance of private parties does not change their essential 

character. As discussed above, since 1980, Congress, concerned with agency resource constraints, has relied on 

third party participation to assist the agency’s evaluation 

of patentability. See also Saint Regis, 896 F.3d at 1330–31

(Dyk, J., concurring). In IPR, Congress imported limited 

discovery and live hearings. As explained in Saint Regis, 

although these modifications to inter partes reexamination 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 21

make IPR “look[] a good deal more like civil litigation,” 

SAS, 138 S. Ct. at 1353, fundamentally these proceedings 

continue to be a “second look at an earlier administrative 

grant of a patent,” Cuozzo, 136 S. Ct. at 2144. See Saint 

Regis, 896 F.3d at 1327–29. The USPTO’s enlistment of 

third parties in IPR has made the process less of an 

“agency-led, inquisitorial process for reconsidering patents,” and more of a “party-directed, adversarial process,” 

SAS, 138 S. Ct. at 1355, i.e., “[an] adversarial, adjudicatory 

proceeding[] between the ‘person’ who petitioned for review 

and the patent owner,” Return Mail, slip op. at 14, but that 

does not disturb the basic purpose of the proceeding, 

“namely, to reexamine an earlier agency decision,” Cuozzo, 

136 S. Ct. at 2144. “Ultimately several factors convince[d]

us that IPR is more like an agency enforcement action than 

a civil suit brought by a private party, and we conclude[d] 

that tribal immunity is not implicated.” Saint Regis, 896 

F.3d at 1327.18 These factors are equally applicable to state 

sovereign immunity. 

First, “[i]t is the Director, the politically appointed executive branch official, not the private party, who ultimately decides whether to proceed against the sovereign.” 

Saint Regis, 896 F.3d at 1328. Although there must be a 

petition for IPR to be initiated (i.e., “[35 U.S.C. § 311(a)] 

doesn’t authorize the Director to start proceedings on his 

own initiative,” SAS, 138 S. Ct. at 1355), any “person who 

is not the owner of [the] patent” may file a petition, 35 

U.S.C. § 311(a), even those who do “not have a concrete 

 

18 We did not hold that interference proceedings were 

barred by state sovereign immunity in Vas-Cath, Inc. v. 

Curators of Univ. of Mo., 473 F.3d 1376, 1382 (Fed. Cir. 

2007), nor do we decide that issue here. We note that interference proceedings may more closely resemble agency adjudication between private parties as compared to IPR 

proceedings.
22 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

stake in the outcome; indeed, they may lack constitutional 

standing,” Cuozzo, 136 S. Ct. at 2143–44. The Director’s decision to institute is within his discretion, and Congress 

went so far as to bar judicial review of that decision. 35 

U.S.C. § 314(d). In this respect, IPR “is not initiated by private parties in the way that a common-law cause of action 

is.” Oil States, 138 S. Ct. at 1378 n.5. 

Second, even if the petitioner or patent owner elects not 

to participate during IPR, the Board can continue to a final 

written decision, “reinforc[ing] the view that IPR is an act 

by the agency in reconsidering its own grant of a public 

franchise.” Saint Regis, 896 F.3d at 1328. In contrast, civil 

litigation in an Article III forum terminates when there is 

no longer a “case or controversy.” 

Third, the IPR procedure is in other respects distinct 

from ordinary civil litigation. The Federal Rules of Civil 

Procedure do not apply. Unlike civil litigation, during IPR 

a patent owner may amend its claims. (In district court litigation, a patent owner may only amend patent claims to 

correct typographical errors). Id. at 1328–29. Even though 

discovery and a live hearing may be part of an IPR proceeding, both are more limited than their civil counterparts. Id. 

It is clear from the history and operation of IPR that 

these proceedings are designed to allow the USPTO to harness third parties for the agency to evaluate whether a 

prior grant of a public franchise was wrong, a feature carried over from inter partes reexamination. In this way, IPR 

is akin to FMC proceedings brought by the agency that 

would not be barred by sovereign immunity. 535 U.S. at 

767–68. Indeed, Saint Regis relied heavily on the Supreme 

Court’s analysis in FMC, which dealt with state sovereign 

immunity. 896 F.3d at 1326 (“Although the precise contours of tribal sovereign immunity differ from those of state 

sovereign immunity, the FMC analysis is instructive.”). 

Applying FMC’s analysis as we did in Saint Regis, we hold 

that IPR, like inter partes reexamination, is similar to an 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 23

agency enforcement action instituted by the USPTO “upon 

information supplied by a private party” rather than civil 

litigation, so state sovereign immunity is not implicated. 

FMC, 535 U.S. at 768.

We also read the Supreme Court’s holding in Oil States, 

that IPR evaluation of patent validity concerns “public 

rights,” as supporting the conclusion that IPR is in key respects a proceeding between the government and the patent owner. In Oil States, the Court concluded that IPR 

proceedings could be conducted before the agency rather 

than an Article III court because they concern matters 

“which arise between the Government and persons subject 

to its authority,” that is “arising between the government 

and others, which from their nature do not require judicial 

determination.” 138 S. Ct. at 1373 (emphases added) (quoting Crowell v. Benson, 285 U.S. 22, 50 (1932)).19 The Court 

concluded that despite the increased participation of third 

parties, IPR “remains a matter involving public rights, one 

‘between the government and others.’” Id. at 1378 (emphasis added) (quoting Ex parte Bakelite Corp., 279 U.S. 438, 

451 (1929)). We interpret the Court’s language in Oil States

as concluding that IPR is an adjudication of public rights, 

and therefore able to be resolved in a non-Article III forum,

because it is in key respects a proceeding between the 

United States and the patent owner. In this way, these proceedings are not barred by state sovereign immunity since

 

19 This is not to say that the public rights doctrine 

may not cover instances of disputes between private parties regarding a public right. See MCM Portfolio LLC v. 

Hewlett–Packard Co., 812 F.3d 1284, 1288–92 (Fed. Cir. 

2015). But we read the Supreme Court as having resolved 

the public rights issue in Oil States on the narrower ground 

that IPR is a proceeding between the United States and the 

patent owner, rather than adjudication between two private parties regarding a public right. 
24 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

sovereign immunity does not bar proceedings brought by 

the United States. FMC, 535 U.S. at 752; Alden, 527 U.S. 

at 755 (citing Principality of Monaco, 292 U.S. at 328–29).

UMN argues that the reasoning in Saint Regis is inapposite to the current appeal because there are salient differences between tribal and state sovereign immunity. In 

Saint Regis we recognized “many parallels” between tribal 

and state sovereign immunity but left “for another day the 

question of whether there is any reason to treat state sovereign immunity differently.” 896 F.3d at 1329. We now 

conclude that the differences between tribal and state sovereign immunity do not warrant a departure from the reasoning in Saint Regis. 

To be sure, “immunity possessed by Indian tribes is not 

coextensive with that of the States,” Kiowa Tribe of Okla.

v. Mfg. Techs., Inc., 523 U.S. 751, 756 (1998), as the two are 

derived from different origins, compare id. at 756–57, with 

Alden, 527 U.S. at 713–28. Tribal sovereign immunity “is 

subject to the superior and plenary control of Congress,” 

Santa Clara Pueblo v. Martinez, 436 U.S. 49, 58 (1978),

whereas state sovereign immunity can only be abrogated 

under “a valid grant of constitutional authority,” Kimel v. 

Fla. Bd. of Regents, 528 U.S. 62, 73 (2000). But, as noted 

above, suits brought by the United States have long been 

recognized as not being impeded by either tribal or state

sovereign immunity, and when Congress intends to abrogate either tribal or state sovereign immunity for suits 

brought by private parties, it must do so with clear language. See, e.g., Michigan v. Bay Mills Indian Cmty., 572 

U.S. 782, 790 (2014) (tribal sovereign immunity); Blatchford v. Native Village of Noatak & Circle Village, 501 U.S. 

775, 786 (1991) (state sovereign immunity).

The patentee’s suggestion that Saint Regis rests on the 

authority of Congress to abrogate tribal sovereign immunity finds no support in the decision or the statutory scheme. 

There is no indication in the AIA or its legislative history 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 25

that Congress designed IPR to abrogate tribal immunity. 

And, contrary to UMN’s arguments, Saint Regis did not 

base its reasoning on implied abrogation of tribal sovereign 

immunity. Instead, Saint Regis concluded that IPR was an

agency reconsideration proceeding to which sovereign immunity does not apply in the first instance. 896 F.3d at 

1329. This reasoning applies equally to states as it does to 

tribes.

UMN further contends that, unlike tribal immunity, 

there is a presumption (the Hans presumption) that state 

sovereign immunity applies to proceedings, such as IPR,

that were “anomalous and unheard of when the Constitution was adopted.” FMC, 535 U.S. at 755–56 (quoting Hans 

v. Louisiana, 134 U.S. 1, 18 (1890)). We disagree. First, “it 

was well understood at the founding that a patent system 

could include a practice of granting patents subject to potential cancellation in the executive proceeding of the Privy 

Council” (i.e., that the executive could provide a forum for 

resolving questions of patent validity). Oil States, 138 S. 

Ct. at 1376–78. Second, the Supreme Court recognized in 

FMC that even though the Hans presumption applied to 

bar resolution of private disputes in an agency forum, it did

not bar resolution of an agency enforcement action against 

a state that was initiated based on information supplied by 

a third party. FMC, 535 U.S. at 767–68. As we held in Saint 

Regis, IPR is properly viewed as an agency’s reconsideration of a previous patent grant that is aided by information 

supplied by a third party, and state sovereign immunity

does not bar these proceedings. 

We conclude that state and tribal sovereign immunity 

do not differ in a way that is material to the question of 

whether IPR proceedings are subject to state sovereign immunity. Thus, under the reasoning of the majority and 
26 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

concurrence in Saint Regis, we conclude that state sovereign immunity does not apply to IPR proceedings. 20

 

20 UMN argues that the Supreme Court’s decision in 

Franchise Tax Board of California v. Hyatt, 139 S. Ct. 

1485, 1495 (2019), recognizes that “the only forums in 

which the States have consented to suits by one another 

and by the Federal Government are Article III courts.” 

UMN contends that this decision supports its position that 

IPR proceedings cannot be maintained even if they are proceedings brought by the United States. Fed. R. App. P. 28(j) 

Letter, ECF No. 155. Unlike the current appeal, Hyatt involved only the question whether state sovereign immunity 

barred private suits brought against a state in a sister 

state’s courts. The Court answered in the affirmative, overruling Nevada v. Hall, 440 U.S. 410 (1979). We do not read 

Hyatt as holding that state sovereign immunity applies in 

agency proceedings initiated by the United States.

First, the sentence in Hyatt relied on by UMN cites 

FMC as sole authority for the proposition. The Supreme 

Court specifically recognized in FMC that an agency “remains free to investigate alleged violations . . . either upon 

its own initiative, or upon information supplied by a private party, and to institute its own administrative proceeding against a [state entity].” 535 U.S. at 768 (citation 

omitted). There is no indication in Hyatt that the Court intended to undermine FMC. Just as the agency could bring 

an enforcement action in FMC, so too can the USPTO institute an IPR proceeding based on information supplied by 

a private party where the final decision is reviewable by an 

Article III court.

Second, even if state sovereign immunity might in 

some circumstances bar administrative proceedings involving states, this would not bar the USPTO’s reconsideration 

of a prior patent grant because a state impliedly consents 

to such proceedings when it applies for, or otherwise 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 27

We finally note, although not implicated in the facts of 

this case, the concerns raised by the parties and amici that 

if sovereign immunity barred IPR proceedings against patents obtained by a sovereign, nothing would prevent a 

state from lending its sovereign immunity to private parties, as the tribe attempted to do in Saint Regis.21 Such manipulation would undo Congress’ central quality control 

mechanism in creating post-grant administrative proceedings. 

CONCLUSION

IPR represents the sovereign’s reconsideration of the 

initial patent grant, and the differences between state and 

tribal sovereign immunity do not warrant a different result 

than in Saint Regis. We therefore conclude that state sovereign immunity does not apply to IPR proceedings. In 

 

obtains ownership of, a patent that is “a creature of statute 

law” and granted “subject to potential cancellation in [an] 

executive proceeding.” Oil States, 138 S. Ct. at 1374, 1377 

(“We conclude that inter partes review is one of th[e] conditions [for patentability].”). When one sovereign acquires 

property under the domain of another, sovereign immunity 

does not bar reconsideration of the property grant by the 

originating sovereign. See Georgia v. City of Chattanooga, 

264 U.S. 472, 479–80 (1924) (“The terms on which Tennessee gave Georgia permission to acquire and use the land 

and Georgia’s acceptance amount to consent that Georgia 

may be made a party to condemnation proceedings.”); Upper Skagit Indian Tribe v. Lundgren, 138 S. Ct. 1649, 

1657–61 (2018) (Thomas, J., dissenting) (discussing the immovable-property exception to sovereign immunity). 21 See Adam Davidson, Why is Allergan Partnering 

With The St. Regis Mohawk Tribe?, The New Yorker, Nov. 

13, 2017 (reporting on interest by state universities in commoditizing sovereign immunity for privately owned patents). 
28 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

light of the above disposition, we do not address the issue 

of whether, if sovereign immunity were to apply to IPR proceedings, the state here waived such immunity by asserting patent claims in district court that were later 

challenged in a petition for IPR.

AFFIRMED

COSTS

No costs.
United States Court of Appeals 

for the Federal Circuit ______________________

REGENTS OF THE UNIVERSITY OF MINNESOTA,

Appellant

v.

LSI CORPORATION, AVAGO TECHNOLOGIES U.S.

INC.,

Appellees

GILEAD SCIENCES, INC.

Intervenor

______________________

2018-1559

______________________

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2017-

01068.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

REGENTS OF THE UNIVERSITY OF MINNESOTA,

Appellant

v.

ERICSSON INC., TELEFONAKTIEBOLAGET LM 

ERICSSON,

Appellees
2 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

GILEAD SCIENCES, INC.

Intervenor

______________________

2018-1560, 2018-1561, 2018-1562, 2018-1563, 2018-1564, 

2018-1565

______________________

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2017-

01186, IPR2017-01197, IPR2017-01200, IPR2017-01213, 

IPR2017-01214, IPR2017-01219.

______________________

Additional views of DYK, WALLACH, and HUGHES, Circuit 

Judges. 

While the opinion for the court does not reach the issue, 

in our view state sovereign immunity also does not apply 

to IPR proceedings because they are in substance the type 

of in rem proceedings to which state sovereign immunity 

does not apply. 

I. In Rem Proceedings

On appeal the parties dispute whether IPR is an in rem 

proceeding to which sovereign immunity does not apply, 

even if the proceedings are deemed adversarial as between 

private parties. 

For sovereign immunity purposes, at least in some contexts the Supreme Court’s “precedent has drawn a distinction between in rem and in personam jurisdiction, even 

when the underlying proceedings are, for the most part, 

identical.” Tenn. Student Assistance Corp. v. Hood, 541 

U.S. 440, 453 (2004). In personam proceedings involve 

“subjecting a State to the coercive process of judicial tribunals at the instance of private parties,” which constitutes 

an affront to a state’s dignity. Id. (quoting Seminole Tribe
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 3

of Fla. v. Florida, 517 U.S. 44, 58 (1996)); see, e.g., id. (“The 

issuance of process . . . is normally an indignity to the sovereignty of a State because its purpose is to establish personal jurisdiction over the State.”). In rem proceedings, 

where personal jurisdiction need not be established over a 

state or its officers, at least in some contexts, “do[] not, in 

the usual case, interfere with state sovereignty even when 

States’ interests are affected.” Cent. Va. Cmty. Coll. v. Katz, 

546 U.S. 356, 370 (2006) (holding that states have waived 

sovereign immunity for certain proceedings brought pursuant to the Bankruptcy Clause). And, as we describe below, 

IPR is an in rem proceeding.

Despite language in some Supreme Court cases 

broadly describing the United States’ immunity to in rem 

proceedings,1 recognition of state sovereign immunity in 

such proceedings has been more limited. For example, 

 

1 See, e.g., The Siren, 74 U.S. 152, 154 (1868) 

(“[D]irect suits cannot be maintained against the United 

States, or against their property . . . .”); but see The Davis, 

77 U.S. 15, 19–20 (1869): “There are some expressions in 

the opinion of this court in the case of The Siren, which 

seem to imply that no suit in rem can be instituted against 

property of the United States under any circumstances. 

But a critical examination of the case and the reasoning of 

the court, will show that that question was not involved in 

the suit, and that it was not intended to assert such a proposition without qualification.” Davis held that personal 

property of the United States in the hands of a common 

carrier is not immune to an in rem “proceeding which does 

not need a process against the United States, and which 

does not require that the property shall be taken out of the 

possession of the United States.” 77 U.S. at 21–22; see also

California v. Deep Sea Research, Inc., 523 U.S. 491, 507 

(1998) (relying on Davis in the context of state sovereign 

immunity).
4 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

sovereign immunity generally bars quiet title actions 

against state-owned real property, particularly where the 

dispute is “over a vast reach of lands and waters long 

deemed by the State to be an integral part of its territory.” 

Idaho v. Coeur d’Alene Tribe of Idaho, 521 U.S. 261, 281–

82 (1997) (citing Tindal v. Wesley, 167 U.S. 204, 223 

(1897)).2 With state-owned personal property, the Court 

has considered whether the disputed property was “owned 

by a state and used and employed solely for its governmental uses and purposes,” because for an ostensibly in rem 

proceeding against the state’s property, “[t]o permit a creditor to seize and sell [the property] to collect his debt would 

be to permit him in some degree to destroy the government 

itself.” In re New York, 256 U.S. 503, 510 (1921) (second 

portion quoting Klein v. City of New Orleans, 99 U.S. 149, 

150 (1878)). In other contexts, the Court has looked to 

whether the state is in actual possession of the disputed 

property: “an actual possession, and not that mere constructive possession which is very often implied by reason 

of ownership under circumstances favorable to such implication.” California v. Deep Sea Research, Inc., 523 U.S. 491, 

507 (1998) (quoting The Davis, 77 U.S. 15, 21 (1869)). This 

is “consistent with the principle which exempts the [State] 

from suit and its possession from disturbance by virtue of 

judicial process.” Id. (alteration in original) (quoting Davis, 

77 U.S. at 21).

IPR is distinguishable from these in rem proceedings 

where the Court has held that sovereign immunity applies. 

Unlike Coeur d’Alene, IPR does not implicate ownership of 

real property or the state’s ability to regulate within its 

 

2 Suits concerning ownership of immovable property 

owned by one sovereign, but located in another, may not 

implicate sovereign immunity. See Upper Skagit Indian 

Tribe v. Lundgren, 138 S. Ct. 1649, 1654–55 (2018); id. at

1657–61 (Thomas, J., dissenting). 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 5

own domain. Cf. Oil States Energy Servs., LLC v. Green’s 

Energy Grp., LLC, 138 S. Ct. 1365, 1376 n.3 (2018) (“Modern invention patents . . . are meaningfully different from 

land patents.”). Patents are creations of federal statutory 

law and are regulated by that law, id. at 1374 (quoting 

Crown Die & Tool Co. v. Nye Tool & Mach. Works, 261 U.S. 

24, 40 (1923)), which includes the ability of the executive to 

consider whether a previous grant was erroneous, id. at 

1376–78 (noting that “[IPR] is one of th[e] conditions” of 

patentability). Patents are also not property that is used by 

a state “solely for its governmental uses and purposes.” 

New York, 256 U.S. at 510.3 Although a state does not 

waive its sovereign immunity merely by participating in 

commercial activity,4 as UMN has done here, such private 

 

3 In recent years states have sought to supplement 

revenue by increasing market participation in licensing 

and enforcing patents. See Andrew Chung, Schools that 

Sue: Why More Universities File Patent Lawsuits, Reuters 

(Sept. 15, 2015); Malathi Nayak, Patent-Heavy Schools 

Look to Courts for IP Paydays, BNA Intellectual Property 

Blog (June 14, 2017); Jacob H. Rooksby, Innovation and

Litigation: Tensions Between Universities and Patents and 

How to Fix Them, 15 Yale J.L. & Tech. 312, 330–40 (2013); 

Tejas N. Narechania, Note, An Offensive Weapon?: An Empirical Analysis of the “Sword” of State Sovereign Immunity 

in State-Owned Patents, 110 Colum. L. Rev. 1574, 1601 

(2010). The federal government’s policy of encouraging 

commercialization of research performed with federal 

funds under the Bayh-Dole Act, Pub. L. No. 96–517, 94 

Stat. 3015 (1980), hardly suggests state sovereign immunity bars administrative reconsideration of an erroneously 

granted patent.

4 Coll. Sav. Bank v. Fla. Prepaid Postsecondary 

Educ. Expense Bd., 527 U.S. 666, 685 (1999) (“[A] suit by 

an individual against an unconsenting State is the very evil 

at which the Eleventh Amendment is directed—and it 
6 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

market participation does not make patents “public property of a state used and employed for public and governmental purposes” that would implicate sovereign 

immunity in in rem proceedings under the Supreme 

Court’s decision in In re New York. Id. at 510. 

Also, because patents are intangible property—a right 

to exclude—the concern of protecting the state’s “possession from disturbance” is not applicable for IPR where ownership is not disputed. Deep Sea, 523 U.S. at 507. A state 

cannot “actual[ly] possess[]” a patent even if the state otherwise claims ownership, see id. (quoting Davis, 77 U.S. at 

21), and the Board does not physically intrude into the 

state’s domain to obtain jurisdiction over a patent or to resolve the issue of its validity. We do not distinguish between tangible and intangible property, but instead 

between property that is physically possessed by a state 

and property that is not. Thus, IPR does not disturb a 

state’s actual possession even if a state-owned patent is 

found to have been erroneously granted.

Not only is an IPR proceeding unlike in rem proceedings held to implicate sovereign immunity, IPR is closely 

akin to proceedings where the Supreme Court has concluded sovereign immunity is not a bar; for example, in rem 

bankruptcy proceedings involving discharge of a debt owed 

to the state. In Tennessee Student Assistance Corp. v. Hood, 

an individual received student loans from the state of Tennessee and then later sought discharge of the state debt in 

bankruptcy proceedings. 541 U.S. at 444–45. She served 

the state with her complaint and a summons. Id. The state 

moved to dismiss the complaint based on state sovereign 

immunity. Id. at 445. The Court held that the state enjoyed 

 

exists whether or not the State is acting for profit, in a traditionally ‘private’ enterprise, and as a ‘market participant.’”).
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 7

no sovereign immunity because of the in rem character of 

the bankruptcy proceedings. 

“The discharge of a debt by a bankruptcy court is . . . 

an in rem proceeding,” id. at 447, as “the court’s jurisdiction 

is premised on the res, not on the persona,” id. at 450. Although “States, whether or not they choose to participate in 

the proceeding, are bound by a bankruptcy court’s discharge order no less than other creditors,” id. at 448, the 

“debtor does not seek monetary damages or any affirmative 

relief from a State by seeking to discharge a debt; nor does 

he subject an unwilling State to coercive judicial process,” 

id. at 450. In this way, “the court’s exercise of its in rem

jurisdiction to discharge a student loan debt is not an affront to the sovereignty of the State.” Id. at 451 n.5.

IPR is similarly an in rem proceeding—a proceeding to 

reevaluate the validity of an issued patent. See Cuozzo 

Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 2144 (2016) (noting “that the proceeding offers a second look at an earlier 

administrative grant of a patent”). Just as with a bankruptcy proceeding to discharge a debt, IPR is an in rem proceeding that is not premised on obtaining jurisdiction over 

a state or its officers. The Board’s jurisdiction is premised 

on the res (i.e., the patent). A person files a “petition to institute an inter partes review of the patent.” 35 U.S.C. § 

311(a) (emphasis added). As in bankruptcy, a petitioner for 

IPR “does not seek monetary damages or any affirmative 

relief from a State by seeking to [have a patent reviewed in 

IPR]; nor does he subject an unwilling State to a coercive 

judicial process.” Hood, 541 U.S. at 450. “[IPR] does not 

make any binding determination regarding ‘the liability of 

[one party to another] under the law as defined.’” Oil 

States, 138 S. Ct. at 1378 (quoting Crowell v. Benson, 285 

U.S. 22, 51 (1932)). The petitioner only seeks to have the 

agency reconsider a previous grant of a patent, and the only 

relief the Board can offer is the revocation of erroneously 

granted patent claims. IPR ultimately terminates only 

with a certificate that either cancels erroneously granted 
8 REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION

patent claims, confirms claims determined to be patentable, or incorporates newly amended claims determined to 

be patentable. 35 U.S.C. § 318(b). No monetary or other relief against the patent owner is authorized or provided.5

Additionally, similar to the state’s situation in Hood, 

there is no statutory requirement compelling a state to participate in IPR as a patent owner, even if it is otherwise 

motivated to do so.6 The parallels between IPR and the 

 

5 To the extent the estoppel provisions in 37 C.F.R. 

§ 42.73(d)(3), prevent a patent owner from obtaining a patent on claims that are patentably indistinct from cancelled 

claims in an IPR proceeding, that result is no different than 

what is mandated under traditional principles of res judicata and collateral estoppel. See B&B Hardware, Inc. v. 

Hargis Indus., Inc., 135 S. Ct. 1293 (2015); MaxLinear, Inc. 

v. CF CRESPE LLC, 880 F.3d 1373 (Fed. Cir. 2018); Ohio 

Willow Wood Co. v. Alps South, LLC, 735 F.3d 1333 (Fed. 

Cir. 2013). In the absence of such a provision, the result 

would still be the same (i.e., the later claim is unpatentable 

for the same reasons as the earlier patentably indistinct 

claim).

6 It is questionable whether a patentee risks default 

by failing to participate in the IPR proceedings. While the 

Board has on occasion interpreted non-participation as 

abandonment under 37 C.F.R. § 42.73(b)(4), see, e.g., VDF 

Futurceuticals, Inc. v. Kazerooni, No. IPR2017–00547, 

2018 WL 842176 (P.T.A.B. Feb. 9, 2018), it is questionable 

whether a default judgment could be entered cancelling a 

patent if the state owner does not participate. See 35 U.S.C. 

§ 313 (“[T]he patent owner shall have the right to file a preliminary response . . . .” (emphasis added)); 37 

C.F.R. § 42.107(a) (“The patent owner may file a preliminary response to the petition.” (emphasis added)); 35 

U.S.C. § 316(a)(8) (requiring regulation “providing for the 

filing by the patent owner of a response to the petition”); 37 
REGENTS OF THE UNIV. OF MINN. V. LSI CORPORATION 9

bankruptcy proceedings in Hood reinforce the conclusion 

that IPR do not raise the concerns that have animated application of sovereign immunity for certain in rem proceedings. 

The USPTO’s “second look at an earlier administrative 

grant of a” public franchise does not constitute an affront 

to a state’s sovereignty, Cuozzo, 136 S. Ct. at 2144, particularly where the only possible adverse outcome is the cancellation of erroneously granted claims. Although patent 

law, like bankruptcy, is a specialized area of law, we see no 

reason why the exercise of the executive’s historically wellrecognized ability to reconsider a grant of a public franchise in an in rem proceeding “is more threatening to state 

sovereignty than the exercise of” an Article III court’s 

bankruptcy in rem jurisdiction. Hood, 541 U.S. at 451. 

Therefore, it seems to us that IPR proceedings are the 

type of in rem proceedings to which state sovereign immunity does not apply.

 

C.F.R. § 42.120 (“A patent owner may file a response to the 

petition . . . .” (emphasis added)). It is the petitioner that 

“shall have the burden of proving a proposition of unpatentability by a preponderance of the evidence.” 35 

U.S.C. § 316(e).