author: BRYSON, Circuit Judge. REYNA, Circuit Judge,

text:
    WI-FI ONE, LLC, Appellant v. BROADCOM CORPORATION, Appellee
    2015-1944
    United States Court of Appeals, Federal Circuit.
    Decided: September 16, 2016

      Douglas AaRon Cawley, McKool Smith, PC, Dallas, TX, argued for appellant. Also represented by Donald Puckett, Nelson Bumgardner PC, Fort Worth, TX; Peter J. Ayers, Lee & Hayes, PLLC, Austin, TX.
    Dominic E. Massa, Wilmer Cutler Pickering Hale and Dorr LLP, Boston, MA, argued for appellee. Also represented by Kevin A. Goldman, Zachary P. PioColomini, Katie Saxton.
    Before DYK, BRYSON, and REYNA, Circuit Judges.
   Concurring opinion filed by Circuit Judge REYNA.

BRYSON, Circuit Judge.

This is an appeal from a decision of the Patent Trial and Appeal Board in an inter partes review. The Board held various claims of a patent owned by Wi-Fi One, LLC (‘Wi-Fi”), to be anticipated. We affirm. .

I

A

The patent at issue, in this case, U.S. Patent No. 6,772,215 (“the ’215 patent”), is directed to a method for improving the efficiency by which messages are sent from a receiver to a sender in a telecommunications system to advise the sender that errors have occurred in a particular message.

In the technology described in the patent, data is transmitted in discrete packets known as Protocol Data Units (“PDUs”). The useful data or “payload” in those packets is carried in what are called user data PDUs (“D-PDUs”). Each D-PDU contains a sequence number that uniquely identifies that packet. The sequence number allows the receiving computer to determine when it either has received packets out of order or has failed to receive particular packets at all, so that the receiver can correctly combine the packets in the proper order or direct the sender to retransmit particular packets as necessary.

The receiver uses a different type of packet, a status PDU (“S-PDU”), to notify the sender of the D-PDUs it failed to receive. The ’215 patent is concerned with organizing the information contained in S-PDUs efficiently so as to minimize the size of the S-PDUs, thus conserving bandwidth.

The patent discloses a number of methods for encoding the sequence numbers of missing packets in S-PDUs. Some of those methods use lists that indicate which packets are missing by displaying the ranges of the sequence numbers of the missing packets. Other methods are based on bitmaps that use binary numbers to report ón the status of a fixed number of packets relative to a starting point.

Depending on how many packets fail to be properly delivered and the particular sequence numbers of the errant packets, different methods can be more or less efficient for encoding particular nümbers and ranges of errors. In order to leverage the benefits of the different encoding methods, the patent discloses an S-PDU that can combine multiple message types in an arbitrary order, with “no rule on the number of messages or the type of'messages that can be included in the S-PDU.” ’215 patent, col: 7, 11. 55-57. Using that technology, S-PDUs can be constructed with a combination of the encoding types best suited for the particular errors being encoded, so that the S-PDU can be more compact than an S-PDU that uses a single encoding type.

B

In 2013, Broadcom petitioned for inter partes review of the ’215 patent, challenging numerous claims. Prior to the institution decision, Wi-Fi argued that Broadcom was barred from seeking review of the patent. Wi-Fi argued that Broadcom was in privity with certain entities that were involved in parallel district court litigation involving the ’215 patent, and that because those entities would be time-barred from seeking inter partes review of the ’215 patent, Broadcom was time-barred as well. See 35 U.S.C. § 315(b).

Wi-Fi filed a motion seeking discovery designed to support its argument, but after briefing the Board denied the motion. It found that Wi-Fi “has not provided evidence to show that there is more than a mere possibility that the sought-after discovery even exists” or “that the sought-after discovery has more than a mere possibility of producing useful evidence on the crucial privity factor” — control of the district court litigation by Broadcom in a way that would foreclose it from seeking inter partes review.

After the Board denied Wi-Fi’s petition for rehearing, Wi-Fi petitioned this court for a writ of mandamus. This court denied the petition. In re Telefonaktiebolaget LM Ericsson, 564 Fed.Appx. 585 (Fed. Cir. 2014).

The Board instituted inter partes review of the ’215 patent, finding that there was a reasonable likelihood that the challenged claims were anticipated by U.S. Patent No. 6,581;176 to Seo. The Board declined to institute review based on another reference because it found that reference would be redundant in light of Seo.

Seo teaches improvements to what are known as negative acknowledgement (“NAK”) frames. NAK frames are sent by the receiving unit to inform the transmitting unit that frames sent by the transmitting unit were misdelivered. The Seo method uses a single packet to provide information about multiple misdelivered frames, so that “only one NAK control frame for all missed user data frames is transmitted to a transmitting station to require a retransmission of the missed user data when a timer for an NAK-is actually expired.” Seo, col. 5, 11. 32-35.

Seo describes the structure of the disclosed NAK frames. The frames include a field called “NAKLTYPE” that indicates how the NAK frame represents missing frames. If the NAK_TYPE is set to “00,” then the missing frames are encoded as a list, and the frame requests retransmission of all user data frames between the first missing frame and the last, represented by the “FIRST” and “LAST” values. If the NAKJTYPE is set to “01,” then the NAK frame transmits information about the missing transmitted frames using a bitmap. In that case, the NAK frame contains the field “NAK_MAP_SEQ” to identify the starting point of the bitmap and the field “NAK_MAP” to transmit the bitmap.

Before the Board, Wi-Fi argued that the NAKLTYPE field disclosed in Seo is not a “type identifier field” and that Seo therefore does not satisfy the type identifier field limitation of the ’215 patent. Wi-Fi further argued that, even if Seo discloses that feature, the NAKJTYPE field is not found within a “message field,” as required by the claims at issue. The Board rejected those arguments, found that Seo disclosed all the limitations of the challenged claims of the ’215 patent, and therefore held those claims to be unpatentable. The Board also rejected Wi-Fi’s argument that claim 15 of the ’215 patent required some sort of “length field,” which Seo did not disclose. Finally, the Board held, that Wi-Fi had not shown that Broadcom was in privity .with the district. court defendants, and therefore Broadcom was not barred from filing a petition for inter partes review.

II

On appeal, Wi-Fi continues to press its argument that Broadcom.was. barred from petitioning for inter partes review because it was in privity with a time-barred district court litigant.

The- Board may not institute inter partes review “if the petition requesting the proceeding is filed more than 1 year after the date on which the petitioner, real party in interest, or privy of the petitioner is served with a complaint alleging infringement of the patent.” 35 U.S.C. § 315(b). To determine whether a petitioner is in privity with a time-barred district court litigant, the Board conducts a flexible analysis that “seeks to determine whether the relationship between the purported ‘privy* and the relevant other party is sufficiently close such that both should be bound by the trial outcome and’ related estoppels.” Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756, 48,759 (Aug. 14, 2012).

This court ' has previously addressed whether a patent owner can argue on appeal that the Board improperly allowed a' privy of a time-barred district court litigant to pursue an inter partes review. The statute governing the Board’s institution of inter partes review provides that “[t]he determination by the Director whether to institute an inter partes review under this section shall be final and nonap-pealable.” 35 U.S.C. § 314(d). In Achates Reference Publishing, Inc. v. Apple Inc., 803 F.3d 652, 658 (Fed. Cir. 2015), we held that section 314(d) “prohibits this court from reviewing the Board’s determination to initiate IPR proceedings based on-its assessment of the time-bar of § 315(b), even if such assessment is reconsidered during the merits phase of proceedings and restated as part of the Board’s final written decision.”

Wi-Fi does not dispute that Ac-hates renders its challenge to the Board’s timeliness ruling nonappealable if Achates is, still good law. What Wi-Fi argues is that the Supreme Court’s recent decision in Cuozzo Speed Technologies, LLC v. Lee, — U.S.-, 136 S.Ct. 2131, 195 L.Ed.2d 423 (2016), implicitly overruled Achates. In Cuozzo the patent owner challenged the Board’s institution decision, arguing that the Board should not have instituted inter partes review, because the petition failed to “identify], in writing and with particularity, each claim challenged, the grounds on which the challenge to each claim is based, and the evidence that supports the grounds for the challenge to each claim.” 35 U.S.C. § 312(a)(3). Based on the language of section 314(d), the Supreme Court held that the Board’s,, decision on that issue was unreviewable. Cuozzo, 136 S.Ct. at 2139. In the course of its opinion, the Court clarified the scope of the preclusion of review:

[I]n- light of § 314(d)’s own text and the presumption favoring review, we- emphasize that our interpretation applies where the grounds for attacking the decision ■ to institute inter partes review consist of questions that are closely tied to the application and interpretation of statutes related to the Patent Office’s decision to initiate inter partes review. This means that we need not, and do not, decide the precise effect of § 314(d) on appeals that implicate constitutional questions, that depend on other less closely related statutes, or that present other questions of interpretation that reach, in terms of scope and impact, well beyond “this section.” Thus, contrary to the dissent’s suggestion, we do not categorically preclude review of a final decision where a petition fails to give “sufficient notice” such that there is a due process problem with the entire proceeding, nor does our interpretation enable the agency to act outside its statutory limits by, for example, canceling a patent claim for “indefiniteness under § 112” in inter partes review. Such “shenanigans” may be properly reviewable in the context of § 319 and under the Administrative Procedure Act, which enables reviewing courts to “set aside agency action” that is “contrary to constitutional right,” “in excess of statutory jurisdiction,” or “arbitrary [and] capricious.”

Id. at 2141-42 (citations omitted).

We see nothing in the Cuozzo decision that suggests Achates has been implicitly overruled. The Supreme Court stated that the prohibition against reviewability applies to “questions that are closely tied to the application and interpretation of statutes related to the Patent Office’s decision to initiate inter partes review.” Section 315 is just such a statute. The time-bar set forth in section 315 addresses who may seek inter partes review, while section 312 governs what form a petition must take. Both statutes govern the decision to initiate inter partes review.

Wi-Fi’s arguments to the contrary are unavailing. Wi-Fi argues that Cuozzo “tied the limitation of judicial review to the Patent Office’s ability to make its substantive patentability determination as embodied in § 314(a).” To the extent that Wi-Fi means to suggest that the Court limited the statutory bar against judicial review to the Board’s substantive determination at the time of institution, i.e., whether a particular" reference raises a reasonable likelihood of anticipating' or rendering a challenged claim obvious, we disagree. The Supreme Court extended the preclusion of judicial review to statutes related to the decision to institute; it did not limit the rule of preclusion to substantive patentability determinations made at the institution stage, as the facts of Cuozzo itself make clear. Subsection 312(a)(3), which the Court addressed in Cuozzo, is not related to substantive pat-entability, but instead is addressed to the conditions for seeking review — in that case, the level of specificity required in the petition.

Wi-Fi also argues that the reviewability ban is limited to issues arising under section 314, because of the statutory text providing that a determination by the Director whether to institute inter partes review “under this section” is not reviewable. 35 U.S.C. § 314(d). This court explicitly rejected that argument in Achates. See 803 F.3d at 658 (“Finally, Achates also contends that § 314(d) does not limit this court’s review of the timeliness of Apple’s petition under § 315, because § 314(d) says ‘[t]he determination by the Director whether to institute an inter partes review under this section shall be final and non-appealable’ (emphasis added). Achates’ reading is too crabbed and is contradicted by this court’s precedent. The words ‘under this section’ in § 314 modify the word ‘institute’ and proscribe review of the institution determination for whatever reason.”). Nothing in Cuozzo casts doubt on that interpretation of the statute, especially in light of the fact that the Supreme Court held that the particularity requirement, which is contained in section 312, is nonappealable.

Wi-Fi next argues that time-bar issues should be reviewable because Board practice allows parties to argue those issues at trial. That argument, too, was rejected in Achates. 803 F.3d at 658 (“That the Board considered the time-bar in its final determination does not mean the issue suddenly becomes available for review or that the issue goes to the Board’s ultimate authority to invalidate — the Board is always entitled to reconsider its own decisions.”). Wi-Fi has not pointed to anything in Cuozzo that casts doubt on that reasoning.

Finally, Wi-Fi argues that the Board’s denial of its request for discovery on the time-bar issue is an example of the “shenanigans” that the Supreme Court in Cuozzo suggested would be reviewable. We disagree. The Board simply declined to grant discovery because Wi-Fi had not made a sufficient showing to support its request. To hold that such a ruling falls within the narrow exception to the Supreme Court’s unreviewability holding would render routine procedural orders reviewable, contrary to the entire thrust of the Cuozzo decision.

Ill

Wi-Fi also challenges the Board’s substantive determination that Seo anticipates the ’215 patent. Wi-Fi brings three separate challenges: that Seo does not disclose a type identifier field, that Seo does not disclose a type identifier field within a message field, and that the Board misconstrued the term type identifier field.

A

Claim 1 of the ’215 patent, which is representative, provides as follows:

A method for minimizing feedback responses in an ARQ protocol, comprising the steps of:
sending a plurality of first data units over a communication link;
receiving said plurality of first data units; and
responsive to the receiving step, constructing a message field for a second data unit, said message field including a type identifier field and at least one of a sequence number field, a length field, and a content field.

Wi-Fi argues that Seo does not disclose a type identifier field because it discloses only a single type of message, and that the single type of message contains fields for encoding errors as both lists and bitmaps. Wi-Fi relies on Figure 4 of Seo, shown below:

Based on Figure 4, Wi-Fi argues that the data structure in Seo contains fields for the list type of coding, which are entitled FIRST, LAST, FCS, and PADDING, and fields for the bitmap type of coding, which are entitled NAK_Map_Count, NAK_Map_SEQ, and NAK_Map.

Wi-Fi argues that in Seo all fields are always present, either as useful values oí-as “padded zeros,” i.e., placeholders, regardless of the value of the NAK-TYPE field. Therefore, Wi-Fi argues, the NAK-TYPE field does not function as a type identifier field that identifies the type of coding used in Seo’s data structure.

The Board rejected that argument, relying on the disclosure in Seo that certain fields “exist” depending on the value of the NAK-TYPE field. See Seo, col. 5,11. 54-57 (“When a value of the field NAK-TYPE is ‘00’, the receiving station requests a retransmission of missed user data frames numbered a field FIRST through a field LAST.”); col. 6,11.18-22 (“If a value of the field NAK-TYPE is ‘01’, the field NAK_MAP_COUNT exists.”). Based on those portions of the Seo specification, the Board concluded that Seo discloses a control frame “that includes certain fields only when NAK-TYPE is ‘00’ and includes other fields only when NAK-TYPE is ‘01.’ ” Accordingly, the Board rejected Wi-Fi’s argument that NAK_TYPE is not a type identifier field.

The Board also credited the testimony of Broadcom’s expert that it would not make sense to include unnecessary fields in a message. It was entirely reasonable for the Board to read the term “exist” in Seo in that way. Substantial evidence therefore supports the Board’s conclusion that Seo discloses the type identifier field feature recited in the ’215 patent.

B

Wi-Fi also argues that even if Seo discloses a type identifier field, Seo does not anticipate the ’215 patent, because the NAI{_TYPE field in Seo is part of the S-PDU header rather than the message field, as required by the .claims.

The Board rejected that argument, finding that the ’215 patent does not require the type identifier field to be in any particular part of. the message, and that, in any event, Seo’s NAKLTYPE field was included in the message field. We agree with the Board. Nothing in the ’215 patent specifies whether the type identifier field must be located .in the header or any other specific part of the message.

Wi-Fi also argues that a prior amendment to claim 1 shows that the claim is drawn to the distinction between the message body and the header. During the prosecution of the ’215 patent, Wi-Fi offered the following amendment:

said message field including a type identifier field and at least one of a type identifier-field, a sequence number field, a length field, and a content field.

That amendment moved the type identifier field from being one of four optional fields to being a required field, accompanied by at least one of the three remaining optional fields.

On appeal, Wi-Fi argues that the amendment-.“distinguishfes], among other things, fields that were included in the header of the PDU such as the ‘PDU-format’ field shown in the admitted prior art.” That argument is meritless. The type identifier field was identified as part of the message field before and after the amendment, so the amendment had no effect on where in the packet the type identifier field had to be located. The amendment simply made that term a required feature, rather than one of the options listed in the “at least one” clause.

That understanding is confirmed by the applicants’ remarks accompanying the amendment. The applicants distinguished a prior art reference by stating that amended claim 1 “provides the type identifier field and -at least one of a sequence number field, a length field, and a content field.” Because there is no support in the patent or the prosecution history for Wi-Fi’s distinction between the presence of the type identifier' field in the message field and in the header, the Board was correct to reject Wi-Fi’s argument.

C

Wi-Fi next argues that the Board erred in construing the phrase “responsive to the receiving step, constructing a message field for a second data unit, said message field including a type identifier field” to mean “a field of a message that identifies the type of that message.” Wi-Fi argues that the Board’s construction failed to specify that a type identifier field must distinguish the type of message from a number of different message types.

We agree with the Board that Wi-Fi’s interpretation does no more than restate what is already clear, from the Boarcl’s construction — that a; type identifier field must distinguish between different message types. Wi-Fi’s real quarrel is not with the Board’s claim construction, but with the Board’s conclusion that Seo discloses different message types. As we have noted, the Board’s conclusion that Seo discloses different message types is supported by substantial evidence. .

rv

Finally, Wi-Fi challenges the Board’s analysis of claim 15. That claim reads:

A method for minimizing feedback responses in an ARQ protocol, comprising the steps of:
sending a plurality of first data units over a communication link; receiving said plurality of first data units; and
responsive to the receiving step, constructing a message field for a second data unit, said message field including a type identifier field and at least one of, a length field, a plurality of erroneous sequence number-fields, and a plurality of erroneous sequence number length fields, each of said plurality of erroneous sequence number fields associated with a respective one of said plurality of erroneous sequence number length fields.

Wi-Fi argues that claim 15, properly construed, requires that the message field contain either a “length field” or an “erroneous sequence number length field.” Because Seo does not disclose length fields of either type, Wi-Fi argues that it does not anticipate claim 15.

Wi-Fi’s argument is based on the structure of the “at least one of’ clause. That clause requires that at least one of the following be present: “a length field,” “a plurality of erroneous sequence number fields,” or “a plurality of erroneous sequence number length fields.” The second entry on the list, “a plurality of erroneous sequence-number fields,” is not by itself a type of length field. However, the final clause of that limitation provides “each of said plurality of erroneous sequence number fields associated with a respective one of said plurality of erroneous sequence number length fields.” That clause, Wi-Fi argues, requires that each erroneous sequence number field must be associated with an erroneous sequence number length field. For that reason, Wi-Fi contends that some sort of length field is required to meet claim 15.

Broadcom argues that the “each of said” clause requires that each of the erroneous sequence number length fields must be associated with an erroneous sequence number field, not the other way around. Therefore, in Broadcom’s view, an erroneous sequence number field can stand-alone, without an accompanying erroneous sequence number length field; for that reason, according to Broadcom, claim 15 does not require the presence of a length field in all cases.

Wi-Fi’s is the better reading of the text of the claim. The structure of the “at least one of’ limitation is best understood by stripping it to its essence: substituting A for the length field, B for the plurality of erroneous sequence number fields, and C for the erroneous sequence number length fields. So viewed, the claim by its terms would require one of A, B, or C, except that each of B must be associated with one of C. That reading is at odds with Broad-com’s, which would require each of C to be associated with one of B.

While the text of the limitation, standing alone, favors Wi-Fi’s interpretation, we conclude that Wi-Fi’s interpretation does not make sense in light of the specification, and thus that Broadcom’s interpretation must be accepted as correct.

The specification of the ’215 patent explains the properties and purpose of the length field. The length field is used in open-ended data structures to provide information about the data structure, such as the number of lists or bitmaps that are present in a packet, or the length of the bitmaps that are used to represent errors. See ’215 patent, col. 2, 11. 56-62; col. 6, 11. 25-34; col. 7,11. 52-65. Because the length of a particular message can be fixed by the rules of the protocol, a length field is not a required feature of the invention. See id., col. 7, 11., 57-60 (“For this exemplary embodiment, each such message includes a type identifier, and the length is either fixed or indicated by a length field for each specific message.”).

The specification also describes the purpose of the erroneous sequence number fields and the erroneous sequence number length fields. The specification explains that one method for representing errors “is to include a field after each list element which determines the length of the error, instead of indicating the length of the err ror with an ‘ending’ [sequence number].” ’215 patent, col. 7, 11. 31-33. Using that method, strings of consecutive errors are represented with an erroneous sequence number that marks the beginning of the error, followed by an erroneous sequence number length field that marks how long the error persists. That method is generally more efficient than representing an error sequence by its starting and ending point because “[i]n most systems, the size of the length field would then be substantially smaller than the-size of the [sequence number] field.” Id., col. 7, -11. 3335.

Figure 9 of the ’215 patent shows how that method would represent the failed transmission of a series of packets numbered 51-77:

The erroneous sequence number field, SNt , shows that the error sequence begins at sequence number 51. The erroneous sequence number length field, L2, shows that the error extends for 27 packets, covering packets 51 through 77.

Based on those descriptions of embodiments of the invention, it is clear that an erroneous sequence number length field is useful only when it is paired with an erroneous sequence number field, while an erroneous sequence number field can be useful without an accompanying erroneous sequence number length field. Thus, an erroneous sequence number field can stand alone, but an erroneous sequence number length field cannot.

The ’215 specification makes clear that an erroneous sequence number field can be used absent an erroneous sequence number length field. As examples, Figure 10 shows four erroneous sequence numbers that are used to indicate errors, and Figure 12 shows a bitmap that contains an erroneous seqúence number field to indicate where the bitmap begins. Both contain erroneous sequence number fields, but not erroneous sequence number length fields, thus supporting the Board’s construction of claim 15.

By contrast, an erroneous sequence number length field can indicate an error only by reference to a starting point, which would be represented by an erroneous sequence number field. The ’215 patent discloses no examples of an erroneous sequence number length field without an accompanying erroneous sequence number field, for the simple reason that an erroneous sequence number length field standing alone would not convey sufficient information to determine.-what packets must be retransmitted.

Based on the full teaching of the specification, we conclude that Wi-Fi’s proposed construction of claim 15 is unreasonable. It would allow an erroneous sequence number length field to be present without an erroneous sequence number field, which the specification indicates would not work, while requiring all erroneous sequence number fields to be associated with erroneous sequence number length fields, which the patent teaches is not necessary. The Board’s construction, on the other hand, comports with what the patent teaches about the number and length fields. Even though the language of claim 15, standing alone, provides some support for Wi-Fi’s interpretation, we hold that in the end the claim must be read as the Board construed it in order to be faithful to the invention disclosed in the specification.

Accordingly, because claim 15, as properly construed, does not require a length field, we hold that the Board was correct to conclude that Seo anticipates that claim.

AFFIRMED

REYNA, Circuit Judge,

concurring.

I agree with the majority that Wi-Fi One has neither shown Broadcom to be in privity with the Texas Defendants nor a real party in interest in the Texas litigation.

I write separately to convey my sense that this Court has jurisdiction to address the time bar question despite the statutory requirement that the Board’s institution decisions “shall be final and nonap-pealable.” 35 U.S.C. § 314(d). I believe that the legal distinction that exists between an “institution” decision and a final decision compels that the decision in this case is a final decision, not an institution decision. A final decision concerning the time bar set forth by 35. U.S.C. § 315(b) should be subject to review. ■

DiscussioN

Our opinion in Achates Reference Publishing v. Apple, Inc., 803 F.3d 652 (Fed. Cir. 2015), holds that a time bar decision is not reviewable — a holding that I believe should be reconsidered by the en banc court. The § 315(b) time bar falls squarely within the exceptions acknowledged by this court in Achates. “[E]ven when the statutory language bars judicial review, courts have recognized that an implicit and narrow exception to the bar on judicial review exists for claims that the agency exceeded the scope of its delegated authority or violated a clear statutory mandate.” Achates, 803 F.3d at 658 (quoting Hanauer v. Reich, 82 F.3d 1304, 1307 (4th Cir. 1996)).

Achates renders § 315(b) toothless. For example, if the Board simply chose to ignore a time bar issue altogether, there would be no avenue for appellate review. I do not believe that is what Congress intended. Rather, I believe §. 314(d) was intended, to ensure that institution decisions were truly preliminary, not to capture all statutory limitations on the inter partes review (“IPR”) process.

Here, the statutory language explicitly allows review of the Board’s final decision, and in this case we- are faced with an argument that the Board exceeded the scope of its statutory authority both in instituting the IPR and in issuing its final decision..

It is clear that not every decision on whether there exists legal basis to commence an IPR is an unreviewable determination by the Director to institute as contemplated under § 314(d). For example, the Supreme Court has noted that § 314(d) may not bar consideration of a constitutional question, but that it “does bar judicial review of the kind of mine-run claim” of whether the grounds stated by the PTO in its institution decision matched the grounds in the original petition for IPR. Cuozzo Speed Techs., LLC v. Lee, — U.S. -, 136 S.Ct. 2131, 2136, 195 L.Ed.2d 423 (2016). The Court noted that Congress did not intend for a final IPR decision to “be unwound under some minor statutory technicality related to its preliminary decision to institute inter partes review.” Id. at 2140.

The time-bar question is not a “mine-run” claim, and it is not a mere technicality related only to a preliminary decision concerning the sufficiency of the grounds that are pleaded in the petition. See Cuozzo, 136 S.Ct. at 2136. Indeed, the time bar question is immaterial to the Board’s initial determination of whether there is a reasonable likelihood the petitioner would prevail on the merits. Rather, the time, bar deprives the Board of jurisdiction to consider whether to institute a review after one year has expired from the date a petitioner, real party in interest, or privy of the petitioner is served with a complaint alleging infringement of the patent. 35 U.S.C. § 315(b). Compliance with the time bar is part of the statutory, basis on which the final decision rests, despite .the fact that the question is first evaluated at the outset of the proceeding and noticed as part of the institution decision.

Cuozzo explicitly notes that its holding does not “enable the agency to act outside its statutory limits” and that such “shenanigans” are properly reviewable. 136 S.Ct. at 2141-42. That admonition compels us to review allegations that the Board has ignored, or erred in the application of, the statutory time bar.

      . Wi-Fi also argues-that even in the absence of a Supreme Court overruling, we. have a license to reconsider Achates because the decision was flawed. We decline Wi-Fi’s "invitation. "We are bound by prior Federal Circuit precedent ‘unless relieved of that obligation by an en banc order of the court or a decision of the. Supreme Cojirt.' ” MCM Portfolio LLC v. Hewlett-Packard Co., 812 F.3d 1284, 1291 (Fed. Cir. 2015) (quoting Deckers Corp. v. United States, 752 F.3d 949, 959 (Fed. Cir. 2014)).

      . A party to an IPR "may appeal the Board’s decision” to this court. 35 U.S.C, § 141(c).


source: Caselaw Access Project

author: REYNA, Circuit Judge.

license: Public Domain

text:
    YEDA RESEARCH AND DEVELOPMENT CO., LTD., Plaintiff-Appellant v. ABBOTT GMBH & CO. KG, Defendant-Appellee Abbott GMBH & Co. KG, Plaintiff-Appellee v. Yeda Research and Development Co., Ltd., Defendant-Appellant
    2015-1662
    2015-1663
    United States Court of Appeals, Federal Circuit.
    Decided: September 20, 2016

      Matthew Nielsen, Marshall, Gerstein & Borun LLP, Chicago, IL, argued for plaintiff-appellant/defendant-appellant. Also represented by Kevin M. FloweRS, Amanda Antons; Roger L. Browdy, Ronni Jillions, Browdy and Neimark PLLC, Washington, DC.

      James Riohard Ferguson, Mayer Brown, LLP, Chicago, IL, argued for defendant-appellee/plaintiff-appellee. Also represented by Todd Ray Walters, Buchanan Inger-soll & Rooney P.C., Alexandria,- VA.
    Before REYNA, WALLACH, and HUGHES, Circuit Judges.
   REYNA, Circuit Judge.

Yeda Research and Development Co., Ltd. (‘Teda”) appeals two decisions by the United States District Court for the District of Columbia — one decided in 2008 (No. 2015-1663) and the other in 2015 (No. 2015-1662). Both district court decisions reviewed determinations by the Board of Patent Appeals and Interferences regarding Yeda’s assertion that Abbott GmbH & Co. KG’s (“Abbott”) U.S. Patent No. 5,344,915 (the “’915 patent”) is invalid as anticipated.

The ’915 patent’s invalidity turns on whether it benefits, from the filing dates from either of two German patent applications — P39 15 072 (the “’072 application”) and P39 22 089 (the “’089 application”). J.A. 5006. If it does, then the field of prior art narrows to exclude the anticipating reference. Whether the ’915 patent is entitled to benefit from the ’072 application’s filing date depends on whether the ’072 application provides adequate written description support for the invention claimed in the ’915 patent.

We affirm the district court’s 2015 decision that Abbott’s ’915 patent is supported by the written description of the ’072 application. As this renders moot Yeda’s appeal No. 2015-1663 concerning the district court’s 2008 decisión, we dismiss that appeal for want of jurisdiction.

BACKGROUND

A. Patented Technology

Abbott’s ’915 patent discloses a protein referred to as TBP-II. TBP-II binds to and neutralizes a protein called Tumor Necrosis Factor A (“TNFA”), which is associated with various immunological diseases. The ’915.patent has three claims. .’915 patent col. 6 11. 37-60. Claim 1 is representative:

1. A purified and isolated TNFA-bind-ing protein which has a molecular weight of about 42,000 dal-tons and has at the N terminus the amino acid sequence
Xaa Thr Pro Tyr Ala Pro Glu Pro Gly Set Thr Cys Arg Leu Arg Glu
where Xaa is hydrogen, a phenylalanine residue (Phe), or the amino acid sequences Ala Phe, Val Ala Phe, Gin Val Ala Phe, Ala Gin Val Ala Phe, Pro Ala Gin Val Ala Phe or Leu Pro Ala Gin Val Ala Phe.

The U.S. application that resulted in the ’915 patent was filed May 4, 1990. It claimed priority to two applications for a “novel protein” — the ’072 application, filed May 9, 1989, and the ’089 application, filed July 5,1989. J.A. 5006.

The prior art in question is the Engel-mann reference, which is an article pub? lished in January 1990 that describes and distinguishes the TBP-I and TBP-II proteins. The parties do not dispute that Engelmann constitutes applicable prior art if the priority date for the ’915 patent is May 1990, but not if the ’915 patent benefits' from the filing date of either the ’072 or the ’089 application. The parties do not dispute that the Engelmann reference anticipates the ’915 patent if the priority date is May 1990.

Neither the ’072 nor the ’089 application discloses the full N-terminus sequence claimed in the ’915 patent. Instead, they disclose a partial N-terminus sequence, a protocol for obtaining the protein from its biological source, and additional properties of the protein, such as molecular weight, biological activity, and degradation characteristics when exposed to trypsin. The parties agree that the only protein containing the N-terminus sequence set forth in the ’072 application is TBP-II — i.e., the same protein claimed in the ’915 patent. J.A. 5024.

B. Procedural History

In 1996, the Board declared Interference No. 103,625 between Abbott’s ’915 patent and Yeda’s Application No. 07/930,-443. The Board assigned Abbott the May 1990 filing date of the application that became the ’916 patent and held that the ’915 patent was invalid as anticipated by Engelmann. Abbott filed suit in federal district court seeking review of the Board’s final decision. In 2008, the district court granted summary judgment for Abbott, holding that the ’089 patent inherently discloses the TBP-II protein and provides an adequate written description of the invention claimed in the ’915 application. The district court vacated the Board’s decision and remanded for further proceedings.

On remand, the Board reversed course. In 2010, the Board held that the ’072 application sufficiently disclosed TBP-II for the ’915 patent to benefit from the ’072 application’s May 1989 filing date. Yeda filed a district court action seeking review of the Board’s 2010 determination. In 2015, the district court affirmed the Board’s decision and granted Abbott summary judgment.

Yeda appeals the district court’s 2008 and 2015 decisions. We have jurisdiction over these appeals pursuant to 28 U.S.C. § 1295(a)(4)(C).

Standard of Review

This court reviews de novo a district court’s grant of summary judgment in an interference action. Boston Sci Scimed, Inc. v. Medtronic Vascular, Inc., 497 F.3d 1293, 1296 (Fed. Cir. 2007). We review de novo the district court’s legal determinations. See Rolls-Royce, PLC v. United Techs. Corp., 603 F.3d 1325, 1330 (Fed. Cir. 2010). The Board’s factual findings, including those relied on by the district court, are reviewed for substantial evidence. In re Gartside, 203 F.3d 1305, 1311-15 (Fed. Cir. 2000). Substantial evidence exists where a reasonable mind could accept it as adequate support for a conclusion. Id. at 1312 (citing Consol. Edison Co. v. NLRB, 305 U.S. 197, 229-30, 59 S.Ct. 206; 83 L.Ed. 126 (1938)).

Discussion

Yeda raises three arguments on appeal. First, Yeda challenges the legal standard applied by the district court to determine whether there was adequate written description support for the ’915 patent in the ’072 application. Second, Yeda argues that the prosecution history precludes Abbott from relying on inherent disclosure. Third, Yeda asserts that the district court erred in holding that the Board’s finding of adequate written description was supported by substantial evidence.

We first address the legal standard for written description support. In' order for the claims of the ’915 patent to benefit from the ’072 application’s filing date, the claimed invention'must be disclosed by the ’072 application. 35 U.S.C. §§ 112, 120; see Kennecott Corp. v. Kyocera Int’l, Inc., 835 F.2d 1419, 1421 (Fed. Cir. 1987). The invention must be disclosed in a way that clearly allows a person of ordinary skill to recognize that the- inventor invented what is claimed and possessed the claimed subject matter at the date of filing. Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc).

Yeda argues that the district court failed to apply the correct test for determining the sufficiency of the written description. According to Yeda, Abbott must show that at the time the ’072 application was filed, a person of ordinary skill in the art would have understood that the partial N-terminus sequence in the ’072 application included the additional amino acids identified in the ’915 patent claims at issue. Abbott responds that the district court correctly held that the ’072 application- need only describe and enable the TBP-II protein, and that a protein can be adequately described when a partial amino acid sequence is disclosed along with other biological characteristics.

Under the doctrine. of inherent disclosure, when a specification describes an invention that has certain undisclosed yet inherent properties, that specification serves as adequate written description to support a subsequent patent application that explicitly recites the invention’s inherent properties. See Kennecott, 835 F.2d at 1423. In this case, it is' undisputed that TBP-II is the only protein with the same partial N-terminus sequence and additional traits disclosed in the ’072 application. J.A. 5024. Therefore, the ’072 application inherently discloses the remaining amino acids in the N-terminus sequence of TBP-II and serves as adequate written description support for the patent claiming TBP-II. It is not necessary for an application to disclose a protein’s complete N-terminus sequence in order to provide an adequate written description of -that protein. Yeda relies on two cases where we declined to find inherent disclosure to argue that the doctrine of inherent disclosure does not extend to this case: Hyatt v. Boone, 146 F.3d 1348 (Fed. Cir. 1998) and In re Wallach, 378 F.3d 1330 (Fed. Cir. 2004). We disagree. Neither Hyatt -nor W'attach involved the situation present in this case, where it is undisputed that the invention described in an earlier application was the exact invention claimed by the later patent.

Yeda also argues that prosecution history belies Abbott’s reliance on inherent disclosure. Yeda notes that in “the context of priority determinations, the allegedly inherent limitation cannot be material to the patentability of the invention.” Yeda asserts that the amino acids missing from the ’072 application are material because Abbott relied upon- their absence to distinguish the. prior art during prosecution of the ’915 patent. See Hitzeman v. Rutter, 243 F.3d 1345, 1355 (Fed. Cir. 2001). The prosecution history, however, does not support Yeda’s argument.

During prosecution of the ’915 patent, the examiner rejected claims based on pri- or art that disclosed a protein with the same source, weight, and function as the protein claimed in the ’915 patent. J.A. 9251. Abbott relied on the Engelmann article to argue thát the cited art concerned only TBP-I, and that TBP-II includes a sequence of five amino acids not present in TBP-I that match the chain recited in the ’915 patent claims. J.A. 9268, 9276-77. Abbott’s response did not solely rely on amino acids missing from the priority applications; three of the five amino acids disclosed in Engelmann were disclosed in the ’072 application and were themselves sufficient to distinguish TBP-I from TBP-II.

Finally, we reject Yeda’s argument that the district court erred- in finding that the Board’s conclusion that the ’072 application provides written description for the ’915 patent is supported by substantial evidence. As the district court noted, the Board’s decision rested on the facts that the ’072 application identified nine of the fifteen amino acids of the N-terminus sequences recited in the relevant claim, as well as several biological characteristics of the protein. J.A. 5028. The parties do not dispute that no known protein other than TBP-II matches these characteristics. The district court correctly found that the Board’s decision was supported by substantial evidence.

Conclusion

Because the ’072 application provides an adequate written description of the protein claimed in Abbott’s ’915 patent, the ’915 patent benefits from the priority date of the ’072 application. We affirm the district court’s 2015 decision. We dismiss Yeda’s appeal No. 2015-1663 from the district court’s 2008 decision for lack of jurisdiction, as it is now moot.

AFFIRMED

Costs

No costs.

      . Dr. Hartmut Engelmann &t at published "Two Tumor Necrosis Factor-Binding Proteins Purified from Human Urine” in the Journal of Biological Chemistry on January 16, 1990. J.A. 5009.


author: SCHALL, Circuit Judge.

text:
    Susan FITZGERALD, Petitioner v. DEPARTMENT OF HOMELAND SECURITY, Respondent
    2015-3154
    United States Court of Appeals, Federal Circuit.
    Decided: September 20, 2016

      John C. Herman, Robbins Geller Rud-man & Dowd LLP, Atlanta, GA, argued for petitioner. Also represented by Carlton Jones, Robert James Leonard.
    Tara K. Hogan, Commercial Litigation Branch, Civil Division, United States Department of Justice, Washington,-DC, argued for respondent. Also represented by Benjamin C. Mizer, Robert E. Kirsohman, Jr., Patricia ' M. MoCarthy, Kristin Mogrory.
    Before DYK, SCHALL, and HUGHES, Circuit Judges.
   SCHALL, Circuit Judge.

Susan Fitzgerald is an employee' of U.S. Customs and Border Protection (“the Agency”), a component of the Department of Homeland Security (“DHS”). She currently works as a “Law Enforcement Specialist (Forensics/Investigative Instructor)” at the Federal Law Enforcement Training Center (“FLETC”) in Glynco, Georgia. In this appeal, she challenges the April 2, 2015 final decision of the Merit Systems Protection Board (“Board”) that sustained the denial by the Agency of her request for secondary Customs and Border Protection Officer (“CBPO”) retirement credit based upon her service as an Instructor at FLETC. J.A. 1-8. For the reasons set forth below, we affirm.

Bacicground

I.

Federal retirement laws extend enhanced benefits to certain groups, such as law-enforcement officers (“LEOs”) and firefighters, who have served in physically rigorous positions. Under the Federal Employees’ Retirement System (“FERS”), those benefits include, inter alia, eligibility to retire with an annuity at an earlier age than many other federal employees and eligibility to retire based on fewer years of service. Compare 5 U.S.C. § 8412(a) (2012) (providing an annuity once an employee has reached the age of 55 and has completed 30 years of service) with id. § 8412(d)(1),(2) (providing an annuity at any age after completing 25 years of service as an LEO or firefighter, or after reaching the age of 50 and completing 20 years of such service). Germane to this case, in 2007, Congress passed legislation (“the Act”) that amended the federal retirement statutes to provide to employees who qualify as CBPOs enhanced retirement benefits similar to those available to LEOs and firefighters-. See Consolidated Appropriations Act, 2008, Pub. L. No. 110-161, § 535, 121 Stat. 1844, 2075-77. The Act became effective on July 6, 2008. See id. § 535(e)(1). As charged by section 535(d) of the Act, the Office of Personnel Management (“OPM”) has issued regulations governing enhanced retirement benefits for CBPOs. See Customs and Border Protection Officer Retirement, 76 Fed. Reg. 41,993 (July 18, 2011) (codified at 5 C.F.R. pt. 842, subpt. J).

II.

Ms. Fitzgerald began her career with the federal government as an Immigration Inspector (GS-1816 series) with the Immigration and Naturalization Service (“INS”) of the Department of Justice. She worked in that capacity from August 2, 1987, to July 2, 1988. Subsequently, from July 3, 1988, to May 6, 2000, she served as a Customs Inspector (GS-1890 series) with the Customs Service (“Customs”) of the Department of the Treasury. Ms. Fitzgerald has been continuously employed in various Instructor positions at FLETC since May. of 2000. One of her main responsibilities while at FLETC has been providing training to criminal investigators and LEOs from various federal organizations.

On August 3, 2012, Ms. Fitzgerald requested that the Agency review her employment history so that she could obtain CBPO retirement credit for her past service with INS and Customs. The Agency denied her request on July 25, 2013, stating that the Act did not provide “retroactive service” credit for service performed before July 6, 2008, the effective date of the Act. Ms. Fitzgerald requested reconsideration and sought CBPO credit for her service at FLETC after the Act’s effective date; the Agency denied her request on April 17, 2014.

III.

Ms. Fitzgerald timely- appealed the denial of her claim to the Board. After conducting a hearing on- September 19, 2014, the administrative judge (“AJ”) to whom the appeal was assigned affirmed the Agency’s denial in an initial decision dated September 29, 2014. Fitzgerald v. Dep’t of Homeland Sec., AT-0831-14-0684-I-1, 2014 WL 4987282 (Sept. 29, 2014) (“Initial Decision”). In arriving at his decision, the AJ examined the pertinent statutory and regulatory framework for determining whether Ms. Fitzgerald is entitled to CBPO retirement credit based upon her service at FLETC.

The Act amended FERS to make CBPOs eligible for enhanced retirement benefits. See Consolidated Appropriations Act, 2008, § 535(b)(2) (codified at 5 U.S.C. § 8412(d)). The Act defines a CBPO as

an employee in [DHS] (A) who holds a position within the GS-1895 job series (determined applying the criteria in effect as of September 1, 2007) or any successor position, and (B) whose duties include activities relating to the arrival and departure of persons, conveyances, and merchandise at ports of entry, including any such employee who is transferred directly to a supervisory or administrative position in [DHS] after performing such duties (as described in subparagraph (B)) in 1 or more positions (as described in subparagraph (A)) for at least 3 years.

Id. § 535(b)(1)(C) (codified at 5 U.S.C. § 8401(36)) (emphasis added). As noted, the amendments made by section 535 of the Act became effective on July 6, 2008. See id. § 535(e)(1). In regard to service performed before its effective date, the Act provides as follows:

(i) GENERAL RULE. — Except as provided in clause (ii), nothing in this section or any amendment made by this section shall be considered to apply with respect to any service performed as a [CBPO] before [July 6, 2008].
(ii) EXCEPTION. — Service described in section ... 8401(36) ... rendered before [July 6, 2008] may be taken into account to determine if an individual who is serving on or after such effective date then qualifies as a [CBPO] by virtue of holding a supervisory or administrative position in [DHS].

Id. § 535(e)(2)(B)(i)-(ii) (emphasis added). Thus, while not retroactive, the Act is retrospective. In other words, it does not allow service rendered before the July 6, 2008 effective date to form the basis for CBPO retirement credit. However, it does permit such prior service to be considered when determining whether a position held in DHS on or after the effective date (Ms. Fitzgerald’s circumstance) qualifies as a “supervisory or administrative” position for purposes of CBPO retirement credit (the question in Ms. Fitzgerald’s case). See 76 Fed. Reg. at 41,994 (explaining that if an individual is in a supervisory or administrative position on July 6, 2008, that individual’s eligibility to be a CBPO will be determined by “looking back at the individual’s employment history to determine whether the requirements for coverage would have been met if the provisions of [section] 535 had been in effect during the earlier employment history”).

Pursuant to its authority to promulgate regulations' to implement the amendments to FERS, OPM issued final regulations governing enhanced retirement benefits for CBPOs on July 18, 2011. The regulations’ definition of CBPO relates to the definition of CBPO in 5 U.S.C. § 8401(36). See 5 C.F.R. § 842.1002. Like the statute, the regulations split CBPOs into two categories of positions (referred to in the regulations as “primary” and “secondary” positions) for which early retirement coverage under 5 U.S.C. § 8412(d) may be available. See id.

Under the regulations, a primary CBPO position is a position “classified within the [CBPO] (GS-1895) job series (determined applying the criteria in effect as of September 1, 2007) or any successor position whose duties include the performance of work directly connected with activities relating to the arrival and departure of persons, conveyances, and merchandise at ports of entry.” 5 C.F.R. § 842.1002. As will be seen, Ms. Fitzgerald does not contend that her employment at FLETC has been in primary CBPO positions. Rather, she argues that her employment at FLETC has been in secondary CBPO positions and that, for that reason, she is entitled to CBPO retirement credit. Pertinent to Ms. Fitzgerald’s claim, a secondary CBPO position is a position in DHS that is either:

(1) Supervisory; i.e., a position whose primary duties are as a first-level supervisor of [CBPOs] in primary positions; or
(2) Administrative; i.e., an executive, managerial, technical, semiprofessional, or professional position for which experience in a primary [CBPO] position is a prerequisite.

Id. (emphasis added).

An employee’s service in a primary CBPO position is automatically “covered,” meaning the service is credited toward retirement eligibility under 5 U.S.C. § 8412(d). See id. § 842.1003(a)(1). However, in order for an employee’s service in a secondary CBPO position to be covered, the regulations require that the service meet certain criteria. See id. § 842.1003(b). With some exceptions not applicable to this case, the employee must have (1) transferred directly (i.e., without a break in service exceeding 3 days) from a primary position to a secondary position, (2) completed 3 years of service in a primary position, and (3) been continuously employed in secondary positions since transferring from a. primary position without a break in service exceeding 3 days. See id. § 842.1003(b)(l)-(3). Because the determination of whether an employee is in a covered secondary position might, as it does here in Ms. Fitzgerald’s case, require consideration of employment periods that occurred before September 1, 2007, the regulations include counterpart definitions of primary and secondary positions solely for the‘purpose of applying the criteria of § 842.1003(b)(l)-(3) to those periods. See id. § 842.1003(c). A primary position in that context (hereinafter, a “Retrospective CBPO Position”) is deemed to include a CBPO position' classified in the GS-1895 series and a predecessor CBPO position that would have been classified in the GS-1895 series had it then existed. See id. § 842.1003(c)(l)(i)-(ii). For the same purpose, the regulations provide that a secondary position in that context includes:

(i) A fírst-lével supervisor of an employee in [a Retrospective CBPO Position]; or
(ii) A executive, managerial, technical, semiprofessional, or professional position for which experience in [a Retrospective CBPO Position] is a mandatory prerequisite.

Id. § 842.1003(c)(2)(i)-(ii) (emphasis added).

Before the Board, Ms. Fitzgerald. did not contend that any of.her Instructor positions at FLETC were primary positions; instead, she argued that they were secondary positions. Thus, to be entitled to CBPO retirement credit for her service at FLETC from the effective date of the Act (July 6, 2008) forward, Ms, Fitzgerald’s prior service had to meet the criteria of § 842.1003(b)(l)-(3) and her Instructor positions after July 6, 2008/ had to be secondary positions under § 842,1002.

In considering Ms. Fitzgerald’s prior service, the AJ began by looking to the rules for service that occurred before September 1, 2007, because Ms. Fitzgerald transferred to FLETC in the year 2000. The AJ found that Ms. Fitzgerald’s positions at INS and Customs qualified as Retrospective CBPO Positions, which meant she had completed the requisite 3 years of service in a primary position before transferring to FLETC. See Initial Decision at 4. Next, the AJ considered whether the Instructor position at FLETC to which Ms. Fitzgerald initially transferred (“the Initial Position”) qualified as a secondary position. The AJ found that “there is no evidence” that the Initial Position qualified as a “first-level supervisor” position under § 842.1003(c)(2)(i). See id, Thus, the AJ explained, in order to meet the requirements of § 842.1003(b)(1), the Initial Position had to be an executive, managerial, technical, semiprofessional, or professional position for which experience in a Retrospective CBPO Position was a mandatory prerequisite, as required -by § 842.1003(c)(2)(ii). See id.

On this point, the AJ looked to the Initial Position’s job description and determined that experience in a Retrospective CBPO Position was not a prerequisite for the position. Rather, the AJ noted, the position description only required experience or knowledge as an LEO. M According to the AJ; although Ms. Fitzgerald acquired the requisite knowledge and skill to qualify for the Initial Position through her years of service in Retrospective CBPO Positions with INS and Customs, the position description included no language suggesting that knowledge or experience unique to CBPOs was required to perform the duties of the Initial Position. See id. at 4-5. The AJ therefore concluded that the Initial Position did not qualify as a secondary position under § 842.1003(c)(2)(ii), Id. at 5. Consequently, the AJ found that Ms. Fitzgerald could not establish that, when she stepped into the Initial Position, she transferred directly from a primary position to a secondary position. Id. She therefore could not establish that her prior service met all of the criteria of § 842.1003(b)(l)-(3). See id.

In addition to her arguments on the merits of her eligibility for CBPO retirement credit, Ms.-Fitzgerald asserted that OPM’s regulations were inconsistent with the statute. The AJ disagreed. In his view, OPM’s interpretation of the phrase “supervisory or administrative position in [DHS] ” in 5 U.S.C. § 8401(36) is entitled to deference because, “at best, the statute is ambiguous” regarding its meaning. See id. at 8 n,2. Accordingly, the AJ affirmed, the Agency’s denial of .Ms. Fitzgerald’s claim for CBPO retirement credit for her service at FLETC from July 6, 2008, onward. Id. at 5.

Ms. Fitzgerald filed a petition for review of the Initial Decision. Echoing the AJ’s reasoning, a ■ two-member panel of the Board denied the petition and affirmed the Initial Decision, which became thq Board’s final decision. See J.A. 1-9, Ms. Fitzgerald timely petitioned for review of the final decision. We- have jurisdiction pursuant to 28 U.S.C. § 1295(a)(9).

Discussion

I.

We review the Board’s decision to determine whether it is “(1) arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law; (2) obtained without procedures required by law, rule, or regulation having been followed; or (3) unsupported by substantial evidence.” 5 U.S.C. § 7703(c) (2012); Miller v. Fed. Deposit Ins. Corp., 818 F.3d 1361, 1365 (Fed. Cir. 2016). “Under the substantial evidence standard, this court reverses the Board’s decision only ‘if it is not, supported by such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.’ ” Shapiro v. Soc. Sec. Admin., 800 F.3d 1332, 1336 (Fed. Cir. 2015) (quoting Abrams v. Soc. Sec. Admin., 703 F.3d 538, 542 (Fed. Cir. 2012)).

Ms. Fitzgerald makes two arguments on appeal. First, she contends that the regulations upon which the Board based its decision should be found invalid for contradicting the plain language of 5 U.S.C. § 8401(36). And second, she urges that, even if the regulations are not invalid, the Board’s decision should be reversed because the Initial Position was a secondary position. We turn first to her challenge to the regulations.

II.

A.

“Our review of questions of statutory interpretation is de nóvo, except to the extent deference to an agency’s construction of a statute it administers is required under the two-step analysis set forth in Chevron.” NSK Ltd. v. United States, 390 F.3d 1352, 1354 (Fed. Cir. 2004) (citation omitted); see also Vassallo v. Dep’t of Def., 797 F.3d 1327, 1330 (Fed. Cir. 2015) (explaining that we review an agency’s statutory interpretation using the two-pronged framework established by Chevron). The first prong of Chevron requires us to assess “whether Congress has directly spoken to the precise question at issue”; if so, we “must give effect to the unambiguously expressed intent of Congress.” Chevron, U.S.A., Inc. v. Nat. Res. Def. Council, Inc., 467 U.S. 837, 842-43, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). If the statute does not answer the specific question at issue, however, meaning that it is “silent or ambiguous,” then, under prong two of Chevron, we must determine whether the' agency provided “a permissible construction of the statute.” Id. at 843, 104 S.Ct. 2778; Hymas v. United States, 810 F.3d 1312, 1318 (Fed. Cir. 2016). “If Congress has explicitly left a gap for [an] agency to fill, .there is an express delegation of authority to.the agency.to elucidate a specific provision of the statute by regulation.” Chevron, 467 U.S. at 843-44, 104 S.Ct. 2778. “Such legislative regulations are given controlling weight unless they are arbitrary, capricious, or manifestly contrary to the statute.” Id. at 844, 104 S.Ct. 2778. In other words, to survive judicial scrutiny, an agency’s interpretation of an ambiguous statute need not be “the only reasonable interpretation or even the most reasonable interpretation.” Yangzhou Bestpak Gifts & Crafts Co. v. United States, 716 F.3d 1370, 1377 (Fed. Cir. 2013) (citation omitted).

Ms. Fitzgerald argues that OPM’s regulations — namely, 5 C.F.R, §§ 842.1002 (defining secondary position) and 842.1003(c)(2) (defining secondary position retrospectively, prior to the effective date of the Act) — impermissibly contradict the plain language and purpose of 5 U.S.C. § 8401(36). In her view, § 8401(36) expressly provides that employees are entitled to CBPO status in a secondary position if they served in a covered primary position for at least 3 years (as she had prior to her transfer to FLETO) and then transferred directly to a supervisory or administrative position in DHS (as she contends she did). Because the statute does not qualify the latter requirement, she reasons, it entitles CBPOs who transferred to any supervisory or administrative position to maintain CBPO status so long as that position is “in DHS.” Ms. Fitzgerald further argues that OPM’s regulations contradict the broad language of the statute by further restricting entitlement to CBPO status to only those CBPOs who transfer or transferred into (a) CBPO-specific supervisory positions or (b) administrative positions that require CBPO-related experience as a prerequisite.

In support of her position, Ms. Fitzgerald avers that OPM’s regulations also conflict with the purpose of the statute. According to Ms. Fitzgerald, the legislative history shows that the Act was intended to help recruit and retain CBPOs by providing to them the same retirement benefits enjoyed by LEOs. The regulations do not promote these goals, she contends, because, under the regulations, CBPOs may not transfer to positions for which their experience is valuable but not a prerequisite without losing their CBPO status and associated retirement credit. Without such flexibility, Ms. Fitzgerald reasons, CBPOs have less incentive to work at DHS.

For its part, the government contends that the statute is silent regarding what constitutes a “supervisory or administrative” position for purposes of CBPO status. Given this silence, and pursuant to its statutory authority to administer the Act, the government ■ argues, OPM promulgated valid regulations that are entitled to deference under Chevron. In the government’s view, Congress’s reliance on OPM to fill the gaps as to the meaning of the term “supervisory or administrative” position is consistent with its approach to retirement benefits for other special groups (e.g., LEOs and firefighters), which indicates it intended for the Act to be implemented in the same manner. The government also suggests that Congress’s silence as to the meaning of this term is consistent with its express delegation of rulemaking authority to OPM to administer the Act.

Regarding prong two of Chevron, the government urges that OPM’s interpretation is based on a permissible construction of the statute. According to the government, the regulations are consistent with the purpose of recruiting and retaining CBPOs because they provide enhanced retirement benefits to CBPOs consistent with those enjoyed by other special groups, and they ensure that senior CBPOs stay in the Agency to share their knowledge and experience with junior CBPOs.

B.

In our view, Congress has not directly spoken to the precise question at issue in this case. We have explained that “[i]dentifying ‘the precise question at issue’ is a necessary prerequisite to determining whether or not Congress has directly spoken on' it.” GHS Health Maint. Org., Inc. v. United States, 536 F.3d 1293, 1297 (Fed. Cir. 2008) (quoting Chevron, 467 U.S. at 842, 104 S.Ct. 2778). The precise question at issue here, we think, is this: what constitutes a supervisory or administrative position in DHS for the purpose of meeting the definition of a CBPO? The statute is silent on this question. See 5 U.S.C. § 8401. Section 8401(36) defines a CBPO to include an “employee who is transferred directly to a supervisory or administrative position in [DHS].” Id. (emphasis added). The terms “supervisory” and “administrative” are not defined within the definition of a CBPO, however. Nor are they defined in any other part of the statute. In fact, the definitions for an LEO and a firefighter also include the “employee who is transferred directly to a supervisory or administrative position” language, but those definitions likewise fail to explain what constitutes a “supervisory or administrative position.” See id. § 8401(14),(17),(33). Consequently, we think the statute does not clearly and unequivocally answer the question at hand.

Congress’s awareness of OPM’s approach to other special retirement groups bolsters our conclusion on the first prong of Chevron. As noted, LEOs and firefighters already received enhanced retirement benefits when the Act was enacted in 2007. Because the statute in place did not define “supervisory or administrative” positions for the purpose of qualifying as an LEO or a firefighter, OPM issued regulations that did. See 5 C.F.R. § 842.802. Given the general presumption that “Congress is knowledgeable about existing law pertinent to the legislation it enacts,” Goodyear Atomic Corp. v. Miller, 486 U.S. 174, 184-85, 108 S.Ct. 1704, 100 L.Ed.2d 158 (1988); see also Minneapolis & St. Louis Ry. Co. v. United States, 361 U.S. 173, 187, 80 S.Ct. 229, 4 L.Ed.2d 223 (1959) (presuming that Congress was aware of applicable regulations when enacting.pertinent'legislation), we agree with the government that Congress likely intended for the framework, for CBPOs to be implemented similarly to that for LEOs and firefighters. Put another way, Congress likely intended to leave a gap as to the meaning of a “supervisory or administrative position in [DHS]” that OPM would fill through regulations. Finally, our view of Congress’s approach to § 8401(36) is also consistent with the Act’s express delegation of rulemaking authority to OPM for the purpose of carrying out the amendments made by the Act. Consolidated Appropriations Act, 2008, § 535(d) (“Any regulations necessary to carry out the amendments made by [section 535] shall be prescribed by the Director of [OPM].”); see also 5 U.S.C. § 8461(g) (providing OPM the authority to “prescribe regulations to carry out the provisions of [FERS] ”).

Contrary to Ms. Fitzgerald’s assertion, neither the statute nor the legislative history clearly demonstrates that Congress intended for secondary CBPO positions to include any supervisory or administrative position in DHS. Section 8401(36) plainly refers to “a” supervisory or administration position, not “any” such position. Accepting Ms. Fitzgerald’s interpretation would impermissibly read the -word “any” into the statute. See Vallee v. Office of Pers. Mgmt., 58 F.3d 613, 615 (Fed. Cir. 1995) (“It is incorrect to read a statute contrary to its plain text, absent compelling evidence of contrary congressional intent.”) Lest there be any doubt on this point, counsel for Ms. Fitzgerald agreed at oral argument before us that § 8401(36) cannot refer to any supervisory or administrative position in DHS. Oral Arg. at 3:34-40, available at http://oralarguments.cafc. uscourts.gov/default.aspx?fl=2015-3154.mp 3 (The Court: So you agree that [§, 8401(36) ] cannot be any-supervisory or administrative position in [DHS], right? Counsel: Correct.).

Accordingly, we conclude that Congress has'not “directly spoken” to the question of'what constitutes a supervisory or administrative position in DHS for the purpose of meeting the definition of a CBPO under § 8401(36). We will therefore defer to OPM’s interpretation as long as it is “a permissible construction of the statute.” Chevron, 467 U.S. at 843, 104 S.Ct. 2778.

C.

Turning to prong two of Chevron, we think 5 C.F.R. §§ 842.1002 and 842.1003(c)(2) are based on á permissible construction of the statute. As noted, the regulations do not conflict with the statute; instead, they merely cabin it by restricting entitlement to CBPO status to employees in certain CBPO-related positions. See 5 C.F.R. §§ 842.1002, 842.1003(c)(2). This restriction is reasonable for at least two reasons. First, it is reasonable to conclude that, for purposes of attaining CBPO sta■tus,. all supervisory and administrative positions in DHS are not created equal. Indeed, there are likely many supervisory and administrative positions in DHS that have no connection to the CBPO occupation. After all, the Agency is only one of many governmental entities in DHS. See 6 U.S.C. § 203; REORGANIZATION Plan Modifi-oation for the.Department of Homeland Security, H.R. Doc. No. 108-32, at 4 (2003). Absent a restriction on where CBPOs in primary positions may transfer, a CBPO might be able to transfer, for example, to a position as an administrative assistant in human resources or to a position as an office administrator — positions for which CBPO experience is presumably neither required nor relevant — while maintaining the benefits of CBPO status for purposes of retirement. We do not think it is unreasonable to conclude that Congress did not intend for.such results to occur. And second, the restriction encourages career service as a CBPO. ,OPM explained that “one policy goal of special retirement coverage is to encourage career service by an employee in the particular occupation chosen by the employee.” 76 Fed. Reg. at 41,996. Enticing employees in primary CBPO positions to transfer into, and remain in, CBPO-related positions in order to maintain CBPO status is a sound method for trying to increase the number of employees who remain in CBPO-related occupations throughout their careers.

In any event, Ms. Fitzgerald does not explicitly argue that OPM’s interpretation is an impermissible construction of the statute. Rather, she asserts that the regulations are inconsistent with the purpose of the Act, which could be read as a contention that the regulations are unreasonable, Either way, we are not persuaded. Ms. Fitzgerald cites legislative history that suggests the purpose of the Act is “to help recruit and retain [CBPOs] by providing them the same retirement benefits as other [LEOs].” H.R. Rep. No. 110-181, at 9 (2008). But even if we accept that the cited legislative history accurately reflects what Congress had in mind when it drafted the Act, the fact remains that the regulations do not limit the retirement benefits of CBPOs as compared to those of LEOs. Instead, they merely restrict who may attain CBPO status in order to obtain the same retirement benefits as LEOs. In addition, while it may be true that more flexible regulations (e.g., ones allowing CBPOs to maintain their CBPO status even after transferring into secondary positions not having the existing, prior-experience requirement) would help recruit and retain CBPOs better than the regulations at issue do, that fact alone does not render OPM’s interpretation unreasonable. See Yangzhou, 716 F.3d at 1377 (explaining that an agency’s interpretation need only represent a “reasonable construction of the statute,” not necessarily “the most reasonable interpretation”) (citation omitted).

Accordingly, because we find that Congress has not answered the specific question at issue- and because we find that OPM has provided a permissible construction of the statute, we conclude that the regulations at issue are not invalid.

III.

A.

We now turn to the Agency’s denial of Ms. Fitzgerald’s claim for retirement credit for her service at FLETC from July 6, 2008, forward.

Ms. Fitzgerald asserts that, even if the regulations at issue are not invalid, the Board incorrectly determined that the Initial Position was not a secondary position. The parties do not dispute that the Initial Position was not a supervisory position under 5 C.F.R. § 842.1003(c)(2)(I). Ms. Fitzgerald also concedes that the job description. for the Initial Position did not explicitly state that experience in customs and border protection was required. Nevertheless, in her view, the job description made clear that the Initial Position required CBPO-related experience because it stated that FLE.TC Instructors must have the knowledge to train LEOs from a “wide variety” of Federal organizations, which she suggests includes the specialized law-enforcement area of customs and border protection. According to Ms. Fitzgerald, FLETC would not have hired her but for her prior experience in Retrospective CBPO Positions. ,

The government responds that there is no evidence in-the record indicating that the Initial Position required experience in a Retrospective CBPO Position. In its view, the job description alone is substantial evidence that an individual could have obtained the Initial Position without ever having served in a Retrospective CBPO Position.

B.

As explained above, in order for Ms, Fitzgerald to prevail on her claim for retirement credit based upon her serving as an Instructor at FLETC, the Board had to find, inter alia, that CBPO experience in a Retrospective CBPO Position was a mandatory prerequisite for the Initial Position, meaning the Initial Position qualified as a secondary position under § 842,1003(c)(2)(ii).- If such experience was not a prerequisite, Ms. Fitzgerald’s service could not meet the criteria of § 842.1003(b). The Board concluded that the job description for the Initial Position indicated that such experience was not a prerequisite. J.A. 6-7. After reviewing the job description, we see no reason to disturb the Board’s conclusion. She 5 C.F.R. § 842.1004(b) (“A determination under § 842.1003(b) must be based on the official position description and any other evidence deemed appropriate by the agency head for making the determination.”).

On its face, the job description only required “[experience in a primary Federal law enforcement position.” See J.A. 351-53. Nor did it implicitly indicate that the requisite experience pertained to work related to the unique duties of an individual in a Retrospective CBPO Position — i.e., work directly connected with activities relating to the arrival and departure of persons, conveyances, and merchandise at ports of entry. See id.; 5 C.F.R. § 842.1003(c)(1). Indeed, as the job title suggested — Law Enforcement Specialist (Instructor) — the listed duties reflect those of someone with prior law-enforcement experience, not necessarily experience in customs and border protection. See J.A. 351-53. Although Ms. Fitzgerald might train a “wide variety” of employees in law enforcement (including CBPOs), and although she might have obtained the Initial Position only by virtue of her prior service in Retrospective CBPO Positions at INS and Customs, that does not establish that her experience in those positions was a “mandatory prerequisite,” as required under the regulations. Instead, it merely indicates that some overlap likely exists between the knowledge and experience required for the Initial Position and that gained by Ms. Fitzgerald while working in those positions.

Accordingly, we conclude that the Board’s decision that Ms. Fitzgerald’s pri- or service did not meet the criteria of § 842.1003(b) and that she therefore is not entitled to CBPO retirement credit for her time at FLETC is supported by substantial evidence.

Conclusion

We hold that 5 C.F.R. §§ 842.1002 and 842.1003(c)(2) are not invalid, because they do not impermissibly contradict the plain language or purpose of 5 U.S.C. § 8401 and because they are based on a permissible construction of the statute. We also hold that the Board’s final decision, which affirmed the Agency’s denial of Ms. Fitzgerald’s request for retirement credit, is supported by substantial evidence. We therefore affirm the final decision.

AFFIRMED

Costs

Each party shall bear its own costs.

      . Congress established FERS in 1986 as a successor to the retirement benefits scheme for federal employees under the Civil Service Retirement System. See Federal Employees’ Retirement System Act of 1986, Pub. L. No. 99-335, § 101, 100 Stat. 514, 516-17; S. Rep. No. 99-166, at 1 (1986). Both systems presently remain in effect; persons employed on or after January 1, 1984, are automatically placed in FERS. See 5 U.S.C. § 8401(11) (1988); 42 U.S.C. § 410(a)(5) (1988). '

      . In March 2003, INS ceased to exist and its functions were transferred to DHS. At the same time, Customs became part of DHS and the agency was renamed the Bureau of Customs and Border Protection. See Homeland Security Act of 2002, Pub. L. No. 107-296, § 1502, 116 Stat. 2135, 2308; Reorganization Plan Modification for the Department of Homeland Security, H.R. Doc. No. 108-32, at. 4 (2003). Subsequently, the agency was renamed U.S. Customs and Border Protection. See Name Change From the Bureau of Immigration and Customs Enforcement to U.S. Immigration and Customs Enforcement, and the Bureau of Customs and Border Protection to U.S. Customs and Border Protection, 72 Fed. Reg. 20,131 (Apr. 23, 2007).

      . The record indicates that Ms. Fitzgerald has been an Instructor at FLETC since May of 2000, even though her position title has ' changed. See J.A. 205, 207, 215, 221.

      . Specifically, § 842.1003(c)(l)(i)-(ii) provides that á Retrospective' CBPO Position includes:
      (i) A position whose duties included the performance of work directly connected with activities relating to the arrival and departure of persons, conveyances, and merchandise at ports of entry that was classified within the Immigration Inspector Series (GS-1816), Customs Inspector Series (GS-1890), Canine Enforcement Officer Series (GS-1801), or any other series which the agency head determines were predecessor series to the Customs' and Border Protection Series (GS-1895), and that would have been classified under the GS-1895 series had it then existed; and
      (ii) A position within the Customs and Border Protection Series (GS-1895) whose duties included the performance of work directly connected with activities relating to the arrival and departure of persons, conveyances, and merchandise at ports of entry.

      . The AJ noted that Ms. Fitzgerald and the Agency disputed the position description under which the Initial Position fell. Initial Decision at 4. However, for the purpose of this case, the AJ assumed that Ms, Fitzgerald’s proffered description was correct. See id. We do too.

      . In light of his determination that Ms. Fitzgerald did not transfer directly from a primary to a secondary position, the AJ added that, even if the Instructor positions to which Ms. Fitzgerald was later assigned qualified as secondary positions, her time at FLETC could not be credited toward retirement because she was employed in the Initial Position for more than. 3 days. See id. at 5. Thus, contrary to the requirements of 5 C.F.R. § 842.1003(b), Ms. Fitzgerald had a break in service exceeding 3 days between a primary, position (the last of her Retrospective CBPO Positions) and the first Instructor position she held after the Initial Position. The AJ accordingly did not determine whether her Instructor positions from July 6, 2008, forward in fact qualified as secondary positions under § 842.1002,

      . Notably, like the regulations for CBPOs, the regulations for LEOs and firefighters also restrict LEO and firefighter status to employees who transfer into (a) LEO- or firefighter-specific supervisory positions or (b) administrative positions that require law-enforcement or firefighting experience as a prerequisite. See 5 C.F.R. § 842.802.

      . In our view, the regulations at issue are likely to achieve the stated "policy goal” because employees will be motivated to maintain CBPO status for at least 25 years (or for at least 20 years if they have reached the age of 50) in order to be eligible for early retirement with an annuity on account of their CBPO status, See 5 U.S.C. § 8412(d)(1),(2). Consequently, employees who start a career as a CBPO will have an incentive to stay in CBPO-related positions for the rest of their careers.