Opinion for the court filed by Circuit Judge SCHALL, in which Senior Circuit Judge FRIEDMAN and Circuit Judges MICHEL, LOURIE, CLEVENGER, RADER, BRYSON, LINN, DYK, and PROST join.
Concurring opinion filed by Circuit Judge DYK, in which Circuit Judge LINN joins.
Dissenting opinion filed by Circuit Judge GAJARSA, in which Chief Judge MAYER and Circuit Judge PAULINE NEWMAN join.
SCHALL, Circuit Judge.James R. Cook appeals the decision of the United States Court of Appeals for Veterans Claims (‘Veterans Court”) in Cook v. West, No. 98-1801, 2000 WL 719866 (Table) (Vet.App. June 1, 2000). In its decision, the Veterans Court upheld the ruling of the Board of Veterans Appeals (“Board”) that the alleged failure of the Veterans’ Administration’s1 Regional Office (“RO”) to give Mr. Cook a proper medical examination before denying his 1952 claim for service-connected benefits did not constitute clear and unmistakable *1336error (“CUE”) under 38 U.S.C. § 5109A. See id. at *2-*5. The Veterans Court also rejected Mr. Cook’s argument that, under Hayre v. West, 188 F.3d 1327 (Fed.Cir.1999), the RO’s alleged failure to give him a proper medical examination rendered the RO’s denial of service connection non-final. Cook, 2000 WL 719866, at *5. Subsequently, a split panel of this court affirmed the decision of the Veterans Court. Cook v. Principi, 258 F.3d 1311 (Fed.Cir.2001), vacated, 275 F.3d 1365 (Fed.Cir.2002). The panel (Mayer, C.J., Friedman, S.J., Rader, J.) held that the Veterans Court did not err in ruling that the RO’s alleged violation of the duty to assist could not serve as the basis for a claim of CUE. At the same time, the panel held that the Hayre exception to the rule of finality did not apply in Mr. Cook’s case. Chief Judge Mayer dissented on the latter point, stating that “a breach of the duty to assist the veteran by failing to provide a proper medical examination vitiates the prior decision of the Regional Office for the purpose of direct appeal.” Cook, 258 F.3d at 1316 (Mayer, C.J., dissenting).
Mr. Cook petitioned for rehearing en banc. In so doing, he argued that, under a proper application of Hayre, a showing that the VA violated any statutory or regulatory duty towards a veteran vitiates the finality of a decision regarding the veteran’s entitlement to benefits. On January 4, 2002, we granted Mr. Cook’s petition for rehearing en banc and vacated the panel opinion. Cook, 275 F.3d at 1366. For purposes of the en banc proceedings, we asked the parties to brief the following two questions:
1. Whether this court’s decision in Hayre v. West, 188 F.3d 1327 (Fed.Cir.1999), should be overruled insofar as that case holds that the existence of “grave procedural error” renders a decision of the Veterans’ Administration non-final?
2. Whether, if Hayre is overruled in this respect, a failure of the Secretary to assist the veteran under the law and regulations applicable at the time (affirmatively demonstrated by the record before the adjudicator in the particular case) can constitute clear and unmistakable error (“CUE”) under 38 U.S.C. § 5109A? See Roberson v. Principi, 251 F.3d 1378 (Fed.Cir.2001).
We answer the en banc questions as follows: First, to the extent that it created an additional exception to the rule of finality applicable to RO decisions, Hayre is overruled. Second, a failure of the Secretary to assist a veteran under applicable law and regulations cannot constitute CUE. In Parts I and II of this opinion, respectively, we address the first and second en banc questions. In Part III, we consider Mr. Cook’s appeal in light of our answers to the en banc questions. Doing so, we affirm the decision of the Veterans Court.
DISCUSSION
I.
A. First En Banc Question
Whether this court’s decision in Hayre v. West, 188 F.3d 1327 (Fed.Cir.1999), should be overruled insofar as that case holds that the existence of “grave procedural error” renders a decision of the Veterans’ Administration non-final?
B. The Rule of Finality
If a veteran fails to appeal from an RO decision concerning a claim, the decision becomes “final,” and “the claim will not thereafter be reopened or allowed, except as may otherwise be provided by regulations not inconsistent with this title.” 38 U.S.C. § 7105(c) (2000). Principles of finality and res judicata apply to agency decisions that have not been appealed and have become final. See Astoria Fed. Savs. *1337& Loan Ass’n v. Solimino, 501 U.S. 104, 107-08, 111 S.Ct. 2166, 115 L.Ed.2d 96 (1991) (allowing the application of res judi-cata to administrative agency determinations that have attained finality); Routen v. West, 142 F.3d 1434, 1437 (Fed.Cir.1998) (applying finality and res judicata to YA decisions). As we observed in Routen, “[u]nless otherwise provided by law, the cases are closed and the matter is thus ended.” Routen, 142 F.3d at 1438.
There are, however, two statutory exceptions to the rule of finality. First, pursuant to 38 U.S.C. § 5108, the Secretary must reopen a claim “[i]f new and material evidence [regarding the claim] is presented or secured.” Second, a decision “is subject to revision on the grounds of clear and unmistakable error.” 38 U.S.C. §§ 5109A (decision by the Secretary) & 7111 (decision by the Board). These are the only statutory exceptions to the finality of VA decisions.2
C. Hayre v. West
In Hayre, the veteran filed a claim in 1972 for service connection for a “nerve problem.” 188 F.3d at 1329. Hayre stated on his claim form that he had been treated while in service for “nerves” and that he had “talked to [a] psychiatrist,” and he requested that the RO obtain his service medical records (“SMRs”). Id. The RO sent a request for the SMRs to the National Personnel Records Center but did not receive them. Id. The RO made no further attempts to obtain the records and rejected Hayre’s claim without notifying him that his SMRs had not been obtained. The RO told Hayre in its denial notice that “we don’t find in your medical records or elsewhere any evidence of a nervous condition.” Id.
In 1992, Hayre again applied for service-connected disability. Following a VA examination, he was awarded service connection and a disability rating for post-traumatic stress disorder. In 1993, seeking an earlier effective date for the award of Service connection, Hayre brought a claim challenging the RO’s 1972 decision as “clearly erroneous.” Hayre argued that the RO had not obtained the psychiatric SMRs that he had requested and had failed to afford him a VA examination. Id. The RO denied the claim, and the Board and the Veterans Court affirmed, treating the claim as a CUE claim.3 Hayre appealed to us.
On appeal, we reversed and remanded. We first held that an RO’s single unsuccessful request for pertinent SMRs that are specifically sought by a claimant does not fulfill the RO’s duty to assist the veteran in developing facts pertinent to his claim.4 Id. at 1331-32. However, relying *1338on Bustos v. West, 179 F.3d 1378, 1381 (Fed.Cir.1999), we held that such a breach of the duty to assist cannot amount to CUE. Hayre, 188 F.3d at 1333.
We next held that the RO’s 1972 decision was not final for purposes of appeal. In so doing, we created a third exception to the rule of finality in addition to the two statutory exceptions created by Congress. Specifically, we held that “where there is a breach of the duty to assist in which the VA failed to obtain pertinent SMRs specifically requested by the claimant and failed to provide the claimant notice explaining the deficiency, the claim does not become final for purposes of appeal.” Id. at 1334. In reaching this holding, we stated that “[i]n cases of grave procedural error, ... the [Veterans Court] has consistently held that RO or Board decisions are not final for purposes of direct appeal.” Id. at 1333 (citing Tablazon v. Brown, 8 Vet.App. 359, 361 (1995); Hauck v. Brown, 6 Vet.App. 518, 519 (1994); Kuo v. Derwinski, 2 Vet.App. 662, 666 (1992); Ashley v. Derwinski, 2 Vet.App. 307, 311 (1992)). We explained that “[a] breach of the duty to assist in which the VA failed to obtain pertinent SMRs specifically requested by the claimant and failed to provide the claimant with notice explaining the deficiency is a procedural error of, at least, comparable gravity [to the errors in the four cited Veterans Court cases] that vitiates the finality of an RO decision for purposes of direct appeal.” Id. We elaborated on the importance of providing adequate notice to the veteran:
Notice to the claimant explaining the failure to obtain pertinent and specifically requested SMRs is ... essential to insuring that the agency of original jurisdiction (“AOJ”) will adequately develop a veteran’s claim before deciding it on the merits. Furthermore, if the claimant is to effectively appeal his or her case, the claimant must be cognizant of all the evidence considered by the AOJ. Where so much of the evidence in VA adjudications is circumstantial at best, notice explaining the failure to obtain pertinent and specifically requested SMRs is critical to ensuring a proper award for benefits and an effective right to judicial review.
Id. at 1334. We thus concluded that if the Veterans Court “finds that the RO breached the duty to assist [Hayre] in 1972, then the 1972 RO decision is not final for purposes of direct appeal.”5 Id. at 1335. We remanded the case to the Veterans Court for further proceedings consistent with our opinion.
D. Whether Hayre Should Be Overruled
The government contends that we should overrule the holding of Hayre that the finality of a VA decision is vitiated if the VA commits a “grave procedural error” when adjudicating a claim. The government argues that the Hayre decision is not supported by statute or legislative history. For his part, Mr. Cook argues that the Hayre decision is consistent with Con*1339gress’ intent to create a system where the veteran is fully and sympathetically assisted in the development of his claims before the VA makes a decision on the merits. He further contends that the- holding in Hayre recognizes the need for a mechanism to allow a veteran to collaterally challenge a VA decision where the veteran later discovers that the VA breached its duty to assist him in developing his claim.
We agree with the government that Hayre should be overruled. The statutory scheme provides only two exceptions to the rule of finality. At the same time, we see nothing in the legislative history of the pertinent statutes—38 U.S.C § 5109A (CUE challenge to an RO decision), 38 U.SC. § 7111 (CUE challenge to a Board decision), 38 U.S.C. § 5108 (reopening of a claim based on new and material evidence), and former 38 U.S.C. § 5107(a) (recognizing the VA’s duty to assist the claimant in the development of his claims) — that indicates that Congress intended to allow additional exceptions to the finality of VA decisions based upon “grave procedural error.”
The purpose of the rule of finality is to preclude repetitive and belated readjudication of veterans’ benefit claims. Congress knew how to create exceptions to the finality of VA decisions, and it explicitly did so in two circumstances. It enacted the statutes codifying CUE challenges (sections 5109A and 7111) and the statute allowing claims based on new and material evidence (section 5108). Applying the familiar canon of expressio unius est exclusio alterius, we conclude that Congress did not intend to allow exceptions to the rule of finality in addition to the two that it expressly created.6 See, e.g., Leatherman v. Tarrant County Narcotics Intelligence & Coordination Unit, 507 U.S. 163, 168, 113 S.Ct. 1160, 122 L.Ed.2d 517 (1993) (applying the expressio unius est exclusio alterius canon in concluding that because Federal Rule of Civil Procedure 9(b) imposes a particularity requirement for pleading two specific types of actions, such particularity is not required for pleading other non-enumerated types of actions); BMW Mfg. Corp. v. United States, 241 F.3d 1357, 1361 (Fed.Cir.2001) (“It thus appears that Congress expressly provided for the exemption of certain merchandise from the [Harbor Maintenance Tax]. Where it did not so provide, it is reasonable to conclude that it did not so intend.”).
In support of its holding that “grave procedural error” vitiates the finality of a VA decision, the Hayre panel relied on the legislative history of the Veterans’ Benefits Amendments of 1989, Pub.L. No. 101-237, § 115(a)(1), 103 Stat.2062, 2065 (1989), which added sections 3004(a)(1) and (2) to title 38 of the United States Code (currently codified as amended at 38 U.S.C. § 5104(a) and (b)). Hayre, 188 F.3d at 1333-34. The relevant provision, section 5104(b), provides that when the VA denies a benefit, the claimant must be provided with a statement of the reasons for the decision and a summary of the evidence considered by the VA; it was effective with regard to VA decisions issued after January 31, 1990. Pub.L. No. 101-237, § 115(b), 103 Stat. at 2066. Section 5104(b) was intended to remedy a lack - of information in VA notices denying claims. S.Rep. No. 101-126, at 294-97 (1989), reprinted in 1989 U.S.C.C.A.N. 1469, 1700-03. There is nothing in the legislative history relating to section 5104(b), however, to indicate that Congress intended that the-lack of information in a pre 1990 VA-decision could support a claim to reopen a final decision.
As noted above, the Hayre panel also relied on four Veterans Court decisions involving “grave procedural error” in sup*1340port of its conclusion that the VA’s single request for Hayre’s SMRs and its failure to notify him of its inability to obtain the records vitiated the finality of the 1972 RO decision. Hayre, 188 F.3d at 1333. We do not think, however, that these cases provide support for the creation of a third exception to the finality of an unappealed VA decision.
An understanding of the process for obtaining disability benefits will help put the four Veterans Court decisions upon which the Hayre panel relied in proper perspective. We outlined the process in Maggitt v. West, 202 F.3d 1370, 1375 (Fed.Cir.1998). A veteran may appeal an adverse RO decision to the Board. Appellate review is initiated by the veteran filing a notice of disagreement (“NOD”) with the VA. See 38 U.S.C. § 7105(a).7 The NOD is a written communication from the veteran expressing dissatisfaction or disagreement with an adjudicative decision of the VA. See 38 C.F.R. § 20.201; Collaro v. West, 136 F.3d 1304, 1308 (Fed.Cir.1998) (explaining that disagreement between the VA and the veteran over legal entitlement to a particular benefit may form the basis of an NOD). Once the VA receives the veteran’s NOD, it must prepare a “statement of the case.” See 38 U.S.C. § 7105(d)(1). The statement of the case “frames the [VA’s] view of the case, and is meant to assist the veteran in gaining every benefit that can be supported in law.” Maggitt, 202 F.3d at 1375. The veteran is required to file a “formal appeal” with the Board within sixty days from the date the statement of the case is mailed. See 38 U.S.C. § 7105(d)(3) (“The appeal should set out specific allegations of error of fact or law, such allegations related to specific items in the statement of the case.”); 38 C.F.R. § 20.202. After the Board renders a decision on the merits of the veteran’s request for benefits, the veteran may appeal the Board’s decision to the Veterans Court. See 38 U.S.C. § 7252(a). A veteran has 120 days from the date of receipt of a Board decision to appeal to the Veterans Court. See 38 U.S.C. § 7266.
In each of the cases cited by the Hayre panel, the Veterans Court held that the time for appealing either an RO or a Board decision did not run where the VA failed to provide the veteran with information or material critical to the appellate process just described. See Tablazon v. Brown, 8 Vet.App. 359 (1995) (because the VA did not furnish the veteran with a statement of the case, he was unable to file a “formal appeal” with the Board and the RO rating decision did not become final); Hauck v. Brown, 6 Vet.App. 518 (1994) (because the veteran never received notification of claim denial in accordance with 38 U.S.C. § 7105(b)(1), the one-year period in which to file an NOD did not begin to run); Kuo v. Derwinski, 2 Vet.App. 662 (1992) (the veteran was not furnished with a statement of the case; therefore, the period in which to lodge a “formal appeal” with the Board did not begin to run); Ashley v. Derwinski, 2 Vet.App. 307 (1992) (since the Board did not mail its decision in accordance with 38 U.S.C. § 7104(e) and 38 U.S.C. § 7266, the 120-day period within which to appeal to the Veterans Court did not begin to run).
Tablazón, Hauck, Kuo, and Ashley involved straightforward application of 38 U.S.C. §§ 7105(b)(1), 7105(d)(3), and 7266. Section 7105(b)(1) provides that the one-year period which the veteran has to file an NOD does not begin to run until the date of the mailing of notice of the claim denial to the veteran. Section 7105(d)(3) makes the furnishing of a statement of the case the event that triggers the veteran’s obligation to file a “formal appeal” with the *1341Board, while pursuant to section 7266, the 120 day period for appealing to the Veterans Court from a decision of the Board does not begin to run until the Board’s decision is mailed to the veteran. In contrast, there is no statutory basis for the Hayre panel’s holding that a breach of the duty to assist the veteran in developing facts pertinent to his claim would vitiate the finality of an RO decision.
Furthermore, in Tablazón, Hauck, Kuo, and Ashley, the VA’s failure to comply with statutory procedural requirements regarding notification of benefit determinations had the effect of extinguishing the claimant’s right to appeal an adverse decision. In Hayre’s case, however, regardless of any failure of the duty to assist in the development of evidence, Hayre was afforded notice of the RO decision denying his claim for service connection. If he had filed an NOD with respect to the 1972 administrative decision, the VA would have been required to provide him with a statement of the case, which would have notified him of the basis for the denial of his claim. See Pub.L. No. 87-666, 76 Stat. 553 (1962) (adding statement-of-the-case requirement at 38 U.S.C. § 4005, currently codified as amended at 38 U.S.C. § 7105). Thus, the VA’s failure to notify Hayre that it had been unsuccessful in obtaining his SMRs did not preclude him from challenging the administrative decision denying his claim and raising the issue of the duty to assist after he was notified of the basis for the decision.8
In summary, a breach of the duty to assist the veteran does not vitiate the finality of an RO decision. We therefore overrule Hayre to the extent that it created an additional exception to the rule of finality applicable to VA decisions by reason of “grave procedural error.” If additional exceptions to the rule of finality in 38 U.S.C. § 7105(c) are to be created, if is for Congress, not this court, to provide them. As we discuss next, however, to the extent it stands for the proposition that a breach of the duty to assist cannot constitute CUE, Hayre remains good law.9
*1342II.
A. Second En Banc Question
Whether, if Hayre is overruled in this respect, a failure of the Secretary to assist the veteran under the law and regulations applicable at the time (affirmatively demonstrated by the record before the adjudicator in the particular case) can constitute clear and unmistakable error (“CUE”) under 38 U.S.C. § 5109A? See Roberson v. Principi, 251 F.3d 1378 (Fed.Cir.2001).
B. The Concept of CUE
CUE provides a means for collateral attack on a final decision of an RO. This concept, once solely grounded in regulation, see 38 C.F.R. § 3.105, is now also governed by statute. In 1997 Congress enacted Pub.L. No. 105-111, 111 Stat. 2271 (1997), which is codified at 38 U.S.C. §§ 5109A and 7111. Section 5109A covers claims of clear and unmistakable error at the RO level, while section 7111 covers claims of clear and unmistakable error at the Board level.10
Although the two provisions are quite similar, only section 5109A, pertaining to review of an RO decision, is relevant to our inquiry. Section 5109A states in relevant part that:
(a) A decision by the Secretary under this chapter is subject to revision on the grounds of clear and unmistakable error. If evidence establishes the error, the prior decision shall be reversed or revised.
(b) For the purposes of authorizing benefits, a rating or other adjudicative decision that constitutes a reversal or revision of a prior decision on the grounds of clear and unmistakable error has the same effect as if the decision had been made on the date of the prior decision.
38 U.S.C. § 5109A.11
The regulation from which section 5109A was derived, and which remains in place today, provides that final determinations of the RO will be accepted as correct unless CUE is shown. See 38 C.F.R. § 3.105(a). Further, like the statute, the regulation provides for the reversal of decisions found to contain CUE and the retroactive award of benefits to the date of the original decision. Id. The pertinent language in the regulation is as follows:
*1343(a) Error. Previous determinations which are final and binding, including decisions of service connection, degree of disability, age, marriage, relationship, service, dependency, line of duty, and other issues, will be accepted as correct in the absence of clear and unmistakable error. Where evidence establishes such error, the prior decision will be reversed or amended. For the purpose of authorizing benefits, the rating or other adjudicative decision which constitutes a reversal of a prior decision on the grounds of clear and unmistakable error has the same effect as if the corrected decision had been made on the date of the reversed decision.
38 C.F.R. § 3.105(a).
The Veterans Court has rendered decisions addressing the meaning of “clear and unmistakable error,” as used in the statute and regulation. In Russell v. Principi, the court addressed for the first time the validity of 38 C.F.R. § 3.105. 3 Vet.App. 310 (1992) (en banc). In upholding the validity of the regulation, id. at 314, the court set forth the parameters of a successful claim of CUE:
By its express terms, 38 C.F.R. § 3.105(a) refers to “determinations on which an action was predicated.” Therefore, it necessarily follows that a “clear and unmistakable error” under § 3.105(a) must be the sort of error which, had it not been made, would have manifestly changed the outcome at the time it was made.
Id.;12 see also Fugo v. Brown, 6 Vet.App. 40, 44 (1993) (“[E]ven where the premise of error is accepted, if it is not absolutely clear that a different result would have ensued, the error complained of cannot be, ipso facto, clear and unmistakable error.”). The requirement that a clear and unmistakable error be one which would have manifestly changed the outcome of the RO’s determination was adopted by this court in Bustos. See 179 F.3d at 1381 (“[T]o prove the existence of CUE as set forth in § 3.105(a), the claimant must show that an outcome-determinative error occurred.”).
In Russell, the Veterans Court also explained that in order for an error to rise to the level of CUE, the error must have been made on the record as it existed at the time the decision was made. See Russell, 3 Vet.App. at 313-314. According to the court, “[a] determination that there was a ‘clear and unmistakable error’ must be based on the record and the law that existed at the time of the prior AOJ ... decision.” Id. (emphasis added). As explained by the Veterans Court in Caffrey v. Brown, 6 Vet.App. 377, 383 (1994), a CUE claim is an attack on a prior judgment that asserts an incorrect application of law or fact. Necessarily, the asserted error must have occurred on the record “as it existed at the time of the disputed adjudication.” Id. We extended this interpretation of the regulation to section 5109A in Pierce v. Principi, 240 F.3d 1348, 1354 (2001) (“We ... affirm the court’s interpretation of the term ‘evidence’ in § 5109A and [38 C.F.R. § 3.105(a)] as being limited to evidence that was of record at the time the challenged RO decision was made.”).
*1344C. Whether a Breach of the Duty to Assist Can Constitute CUE
Mr. Cook urges us to overrule precedent holding that a breach of the duty to assist cannot serve as a basis for CUE. See Hayre, 188 F.3d at 1333 (stating that “a breach [of the duty to assist] is not an error of the sort that should be contemplated in the CUE analysis”); Caffrey, 6 Vet.App. at 384 (stating that “the VA’s breach of the duty to assist cannot form a basis for a claim of CUE because such a breach creates only an incomplete rather than an incorrect record”). Mr. Cook advances three arguments in support of his position. First, he contends that requiring the CUE analysis to be conducted on the record as it existed at the time of the original decision is flawed. He argues that the proper interpretation of section 5109A allows for all evidence of error to be considered in reviewing a CUE claim, not just evidence that was a part of the original record. Second, Mr. Cook urges that the requirement that an error must be outcome determinative in order to constitute CUE, stated in Bustos, see 179 F.3d at 1381, and relied on in part by Hayre in its rejection of Hayre’s CUE claim, see 188 F.3d at 1333, is also flawed. Mr. Cook urges that a lesser standard should be applied consistent with the goal of “fundamental fairness.” He suggests that a lesser standard for CUE was advanced by this court in Roberson v. Principi, 251 F.3d 1378 (Fed.Cir.2001). For its part, the government argues that the interpretations of 38 C.F.R. § 3.105 and 38 U.S.C. § 5109A discussed above are supported by the statute and legislative history and, therefore, should be upheld.
We agree with the government that a breach of the duty to assist cannot constitute CUE. Both our precedent and that of the Veterans Court establish two requirements for a CUE claim. First, in order to constitute CUE, the alleged error must have been outcome determinative, see Bustos, 179 F.3d at 1381; second, the error must have been based upon the evidence of record at the time of the original decision, see Pierce, 240 F.3d at 1354. As explained below, in order to hold that a breach of the duty to assist can form the basis for a CUE claim, we would have to jettison these requirements. We do not think that such a change in the law is warranted.
Turning first to the requirement that the alleged error be outcome determinative, we note that both the regulation and the statute provide that once a prior decision is found to contain clear and unmistakable error it is to be “reversed.” See 38 C.F.R. § 3.105(a); 38 U.S.C. § 5109A. The call for reversal on account of clear and unmistakable error clearly suggests that the contemplated error is outcome determinative. See id.
The legislative history of section 5109A also supports the conclusion that an alleged error must be outcome determinative in order to constitute CUE. We have held that Congress’ intent in drafting section 5109A was to codify and adopt the CUE doctrine as it had developed under 38 C.F.R. § 3.105. See Pierce, 240 F.3d at 1353 (noting that the legislative history of section 5109A “reveals Congress’ awareness and approval of the decision of the Veterans Court in Russell,” and pointing out that the House and Senate Reports, see H.R.Rep. No. 105-52, at 2-3, and S.Rep. No. 105-157, at 3, “discuss Russell as setting forth the current state of the law which was to be codified by § 5109A”); Donovan v. West, 158 F.3d 1377, 1382 (Fed.Cir.1998) (“Pub.L. No. 105-111 ... made no change in the substantive standards in the regulation governing modifications of a regional office decision because of ‘clear and unmistakable error.’ ”); Bustos, 179 F.3d at 1381 (“38 U.S.C. § 5109A *1345made no change to the substantive standards governing modifications of RO decisions because of CUE ... This statutory provision merely codified 38 C.F.R. § 3.105 and the Court of Appeals for Veterans Claims’ long standing interpretation of CUE.”). As stated in the legislative history, the purpose of the bill was to “effectively codify [38 C.F.R. § 3.105], and extend the principle underlying it to BVA decisions.” H.R.Rep. No. 105-52, at 2 (1997). In addition, Congress explicitly endorsed the Russell interpretation of CUE. The House Report to Pub.L. No. 105-111 cites liberally to the Russell and Fugo opinions in its discussion of CUE, including the following language from Fugo:
It must always be remembered that clear and unmistakable error is a very specific and rare kind of “error”. It is the kind of error, of fact or of law, that when called to the attention of later reviewers compels the conclusion, to which reasonable minds could not differ, that the result would have been manifestly different but for the error. Thus even where the premise of error is accepted, if it is not absolutely clear that a different result would have ensued, the error complained of cannot be, ipso fac-to, clear and unmistakable. Russell v. Principi, 3 Vet.App. 310, 313 (1992) (en banc).
H.R.Rep. No. 105-52, at 3 (quoting Fugo, 6 Vet.App. at 44). The Senate Report cites to Russell in its explanation of the doctrine of CUE: “CVA has ruled that ‘clear and unmistakable error’ is error that is obvious and was outcome determinative with respect to the decision under review.” S.Rep. No. 105-157, at 3.
We turn now to the second requirement of CUE. As noted above, in Russell, the Veterans Court held that a determination that there was CUE must be based upon the record that existed at the time of the original RO decision. We have held,that the legislative history of section -5109A supports the requirement that the CUE analysis be limited to the record before the prior adjudicator. In Pierce, we stated that “[although the language of § 5109A does not expressly limit the evidence that can be considered in a CUE challenge to evidence that was of record at the time the challenged decision was made, the legislative history of the statute, the purpose of the statute, and the overall statutory scheme for reviewing veterans’ benefits decisions all indicate that Congress intended the evidence to be so limited.” 240 F.3d at 1353. In addition, we pointed out that “[a]lthough the House and Senate reports do not expressly discuss Russell’s holding with respect to the evidence that can be considered when evaluating a CUE claim, they do discuss Russell as setting forth the current state of the law that was to be codified by § 5109A.” Id. Significantly, the House Report explains, “[t]his bill addresses errors similar to the kinds which are grounds for reopening Social Security claims. Under the Social Security system, a claim may be reopened at any time to correct an error which appears on the face of the evidence used when making the prior decision.” H.R.Rep. No. 105-52, at 3 (emphasis added).
We conclude that decisions of this court and the Veterans Court concluding that a clear and unmistakable error at the RO level must be outcome determinative and must be apparent from the evidence of record at the time of the original decision are supported by the language of 38 U.S.C. § 5109A and its legislative history. We therefore reject Mr. Cook’s request that we overturn existing law to that effect.13
*1346The requirements that a clear and unmistakable error be outcome determinative •and be based on the record that existed at the time of the original decision make it impossible for a breach of the duty to assist to form the basis for a CUE claim. First, a breach of the duty to assist cannot constitute an outcome determinative error. Without the benefit of additional evidence that might have been in the record but for the breach, we may only conclude that, as a result of the breach, the record was incomplete. This cannot be an “outcome-determinative” error. In Cqffrey, the Veterans Court explained that
[w]hile it is true that an incomplete record may ultimately lead to an incorrect determination, it cannot be said that an incomplete record is also an incorrect record. If the facts contained in the record are correct, it is not erroneous, although not embodying all of the relevant facts. Rather, an incomplete record is just that — incomplete.... Thus, an incomplete record, factually correct in all other respects, is not clearly and unmistakably erroneous.
Caffrey, 6 Vet.App. at 383. Second, a breach of the duty to assist necessarily implicates evidence that was not before the RO at the time of the original decision. In accordance with the duty to assist, the VA is required to help a veteran in obtaining evidence in support of his or her claim. See 38 U.S.C. § 5103A. If the VA breaches this duty, the result is that the RO considers the veteran’s claim on a record that is incomplete because it does not include all the pertinent evidence. Incomplete or not, however, as explained above, the only record that may be reviewed in the CUE analysis is the record that was before the RO at the time of the original decision. Evidence that should have been part of the record, but was not (because of a breach of the duty to assist), may not be considered. In sum, a breach of the duty to assist cannot constitute CUE.
Finally, we do not agree with Mr. Cook that Roberson v. Principi supports the proposition that a breach of the duty to assist can form the basis for a CUE claim. In Roberson, a panel of this court reviewed the Veterans Court’s rejection of a CUE claim that was based on an alleged breach of the duty to assist relating to a 1984 rating (percentage of disability) decision. We explained that, “[a]s we held in Hayre v. West, 188 F.3d 1327, 1332-33 (Fed.Cir.1999), breach of the duty to assist cannot *1347form the basis for a CUE claim.” Roberson, 251 F.3d at 1384.
Having rejected the argument that a breach of the duty to assist could serve as the basis for a CUE claim, we went on to “determine the standard that applies when the VA is considering a CUE claim.” Id. We concluded that, in adjudicating a CUE claim, the VA is required to follow the approach outlined in Hodge v. West, 155 F.3d 1356 (Fed.Cir.1998), for the situation in which a veteran seeks to reopen a disallowed claim based upon new and material evidence under 38 U.S.C. § 5108. Roberson, 251 F.3d at 1384. In Hodge, we stated that the VA is “to fully and sympathetically develop the veteran’s claim to its optimum before deciding it on the merits.” 155 F.3d at 1362. In Roberson, a critical issue was whether, in addressing Roberson’s claim' that there was CUE in the 1984 rating decision, the VA and the Veterans Court had erred by failing to recognize that in his original claim, Roberson had sought total disability based upon individual unemployability (“TDIU”). We concluded that, in line with the Hodge rubric, once a veteran submits evidence of a medical disability and makes a claim for the highest rating possible and also submits evidence of unemployability, the VA must consider TDIU. We stated that, in order to develop a claim “to its optimum,” as required by Hodge, the VA “must determine all potential claims raised by the evidence, applying all relevant laws and regulations, regardless of whether the claim is specifically labeled as a claim for TDIU.” Roberson, 251 F.3d at 1384. We therefore reversed the holding of the Veterans Court that Roberson had failed to make a claim for TDIU before the RO in 1984. Id. We remanded the case to the court for consideration of Roberson’s appeal of the denial of his CUE claim in light of our decision. Roberson does not support Mr. Cook’s contention that a breach of the duty to assist may constitute CUE.
III.
Having held that there can be no judicially crafted exception to the rule of finality and that a breach of the duty to assist cannot constitute CUE, we turn now to the facts of this case.
Mr. Cook served in the United States Army from August of 1942 to December of 1945. His service medical records contain a March 1945 diagnosis of “psychoneurosis, anxiety type.” When he was recalled for service in 1950, an examination found that he was “not qualified for active duty due to his ulcer.” In 1952, Mr. Cook submitted a benefits claim to the RO for service connection for “Stomach Trouble Nervous Stomach.” A physical examination revealed a duodenal ulcer. In a neu-ropsychiatric examination the attending physician noted:
The present day idea is, generally, that a peptic ulcer may be a visceral expression of long continued anxiety. In this case, a diagnosis of duodenal ulcer has been established. A dual diagnosis should not be made, but it should be clear that the diagnosis of duodenal ulcer includes a psychic or emotional component.
In June of 1952, the RO denied service connection for “stomach trouble and nervousness.” It stated that Mr. Cook’s ulcer was not incurred or aggravated in sendee and that the most recent examination had not revealed nervousness. The RO also stated that the “[neuropsychiatric] examination revealed no evidence of a psychiatric disability.”
Mr. Cook did not appeal the RO decision to the Board; it therefore became final. See 38 U.S.C. § 709 (1952).14 In July of *13481989, Mr. Cook sought to reopen his claim. The Board did so and denied service connection. The Veterans Court, however, reversed and directed the Board to determine Mr. Cook’s rating for both his nervous disorder and his ulcer. Cook v. Brown, 4 Vet.App. 231, 238 (1993). Thereafter, the RO awarded Mr. Cook a thirty percent rating for his anxiety disorder and a zero percent rating for his duodenal ulcer. The RO made the awards effective as of July 1989 (when Mr. Cook had sought reopening of his claims).
Mr. Cook appealed the RO’s decision, contending that the effective date of the award should have been the April 1952 date of the original filing of his claim and that the RO’s 1952 decision contained CUE and therefore was non-final.15 The Board rejected Mr. Cook’s contention that the 1952 regional office decision constituted CUE, and Mr. Cook appealed to the Veterans Court. While the appeal was pending at the Veterans Court, Hayre was decided. The Veterans Court ordered briefing by the parties as to the application of Hayre to Mr. Cook’s case.
Subsequently, in a single-judge unpublished decision, the Veterans Court affirmed the decision of the Board. The court first held that the alleged deficiencies in the RO’s 1952 decision did not constitute CUE. The court then rejected Mr. Cook’s argument that the RO’s failure to give him an adequate medical examination in 1952 violated its duty to assist him, so as to render the 1952 decision not final and make the date of that decision the effective date of his benefits. As to whether Mr. Cook’s claim fit within the exception to the rule of finality created by Hayre, the court concluded that even if Mr. Cook had established a breach of the duty to assist, the failure to provide him with an appropriate medical examination did not rise to the level of the “grave procedural error” found in Hayre.
We affirm the decision of the Veterans Court. In Part I of this opinion, we have overruled Hayre insofar as it holds that the existence of “grave procedural error” renders a decision of the VA non-final. In Part II, we have held that a failure of the VA to assist the veteran to the extent required by applicable law and regulations cannot constitute CUE under 38 U.S.C. § 5109A. In the face of these rulings, Mr. Cook’s claim for an earlier effective date for his service-connected disability benefits must fail, because the rulings leave Mr. Cook without any ground upon which to claim an earlier effective date.
CONCLUSION
For the foregoing reasons, the decision of the Veterans Court is affirmed.
COSTS
No costs.
AFFIRMED.
. The Veterans’ Administration was renamed the Department of Veterans Affairs in 1988. Department of Veterans Affairs Act, Pub.L. No. 100-527, 102 Stat. 2635 (1988). Throughout this opinion, "VA” will be used as an abbreviation for both the Veterans' Administration and the Department of Veterans Affairs.
. We have held that a veteran may bring a claim having the same factual basis as a previously disallowed claim when an intervening and substantive change in law or regulation creates a new basis for entitlement to a benefit. See Spencer v. Brown, 17 F.3d 368, 372 (Fed.Cir.1994); Routen, 142 F.3d at 1438. Such a claim is treated as a new claim, however, and not a request for reconsideration of a previously disallowed claim. See Spencer, 17 F.3d at 372.
. A veteran who successfully brings a CUE claim is entitled to benefits retroactive to the date of the original claim. See 38 U.S.C. § 5109A(b) ("For the purpose of authorizing benefits, a rating or other adjudicative decision that constitutes a reversal or revision of a prior decision on the grounds of clear and unmistakable error has the same effect as if the decision had been made on the date of the prior decision.”).
.When Hayre was decided, the statutory duty to assist was set forth at 38 U.S.C. § 5107(a) (1994) (“The Secretary shall assist such a claimant in developing the facts pertinent to his or her claim.”). In enacting 38 U.S.C. § 5107(a) as part of the Veterans' Judicial Review Act, Pub.L. No. 100-687, § 103(a), 102 Stat. 4105, 4106 (1988), Congress codified the VA's obligation to assist claimants, *1338which had existed in 38 C.F.R. § 3.103(a) since 1972. See 38 C.F.R. § 3.103(a) (1987) ("[I]t is the obligation of [the VA] to assist a claimant in developing the facts pertinent to his [or her] claim....”); Hayre, 188 F.3d at 1331. The duty to assist is now codified at 38 U.S.C. § 5103A(a) ("The Secretary shall make reasonable efforts to assist a claimant in obtaining evidence necessary to substantiate the claimant's claim for a benefit under a law administered by the Secretary.”). Section 5103A(a) was added to the statutory scheme when Congress enacted the Veterans Claims Assistance Act of 2000, Pub.L. No. 106-475, 114 Stat. 2096 (2000). See id., § 3(a), 114 Stat. at 2097. The regulation setting forth the duty to assist remains unchanged. See 38 C.F.R. § 3.103(a) (2000).
. Pursuant to the Veterans Claims Assistance Act, the VA, as part of the duty to assist, is required to notify a claimant when it is unable to obtain relevant records. See 38 U.S.C. § 5103A(b)(2).
. Expressio unius est exclusio alterius means that "the expression of one thing is the exchision of another.” Harris v. Owens, 264 F.3d-1282, 1296 (10th Cir.2001).
. The appeal period is one year ''from the date of mailing of notice of the result of initial review or determination.” 38 U.S.C. § 7105(b)(1).
. If on direct review, the Veterans Court concludes that there was a breach of the duty to assist, it may vacate the decision on appeal and remand the case to the VA for further consideration following compliance with the duty to assist. See Pond v. West, 12 Vet.App. 341, 346 (1999).
. Our dissenting colleague, Judge Gajarsa, believes that an applicant for veterans' benefits possesses a property interest of sufficient magnitude to invoke the protection of the Fifth Amendment's Due Process Clause. Starting from that premise, he would hold that, where a breach of the duty to assist results in the denial of benefits, application of the rule of finality is tantamount to a denial of due process and, accordingly, the rule should be vitiated. Thus, Judge Gajarsa would create a new exception to the rule of finality, in order to obviate what he perceives to be a procedural due process violation arising from a breach of the duty to assist.
The Due Process Clause question was not briefed by the parties or argued to us. Nevertheless, assuming arguendo that a breach of the duty to assist may implicate the Due Process Cláuse, we note that the claim adjudication process before the RO and the Board has long provided a structure that affords a veteran a hearing. See 38 C.F.R. §§ 3.3-3.14; 19.0-19.7 (1949). During the adjudication of his claim, a veteran may always assert that there has been a breach of the duty to assist. Moreover, as noted, under the regime that has existed since 1988, if the Veterans Court determines that the VA failed to comply with the duty to assist, the court may vacate the decision being appealed and remand the case for further consideration in compliance with the duty to assist. Pond, 12 Vet.App. at 346.
If, however, a breach of the duty to assist is not known to the veteran during the adjudication of his claim, and becomes known to the veteran only after the decision to deny his claim for benefits has become final, the veteran may only apply to have the final judgment reopened through the two avenues provided by Congress, CUE and new and material evi*1342dence. These two avenues constitute significant departures from the normal rule that final judgments cannot be reopened. For the reasons stated infra in this opinion, a breach of the duty to assist may not form the predicate for a CUE claim. Whether it is possible for a veteran to ameliorate the potential harm of a breach of the duty to assist with a claim of new and material evidence is not a matter before us. In any event, the possibility that an error may occur during the claim adjudication process is not a reason to hold the process in violation of the Due Process Clause and therefore vitiate the rule of finality.
. Before the enactment of section 7111, the concept of CUE with respect to Board decisions was not recognized. See Smith v. Brown, 35 F.3d 1516, 1526-27 (Fed.Cir.1994) (''[T]he Secretary correctly interpreted CUE review authority in 38 C.F.R. § 3.105(a) as relating only to review of AOJ adjudicatory decisions and not to those of the Board.”).
. S ection 7111 states in relevant part that:
(a) A decision by the Board is subject to revision on the grounds of clear and unmistakable error. If evidence establishes the error, the prior decision shall be reversed or revised.
(b) For the purposes of authorizing benefits, a rating or other adjudicative decision of the Board that constitutes a reversal or revision of a prior decision of the Board on the grounds of clear and unmistakable error has the same effect as if the decision had been made on the date of the prior decision.
38 U.S.C. § 7111.
. Russell addressed a prior version of the CUE regulation. In that version, the first sentence of section 3.105(a) differed slightly from its present counterpart. It read as follows:
"Previous determinations on which an action was predicated, including decisions of service connection, degree of disability, age, marriage, relationship, service dependency, line of duty, and other issues will be accepted as correct in the absence of clear and unmistakable error.” Russell, 3 Vet.App. at 312-313.
. As noted above, review of Board decisions for CUE is governed by 38 U.S.C. § 7111. The VA has promulgated Board rules imple-meriting section 7111. See 38 C.F.R. §§ 20.1400 1411. Although neither section *13467111 nor its implementing rules are before us today, it is worth noting that the rules adopt the requirements that in order for an error to rise to the level of CUE, it must be outcome-determinative and must be based upon the record before the Board when it rendered its original decision. Rule 1403 states that, for there to be CUE, “there must have been an error in the Board's adjudication of the appeal which, had it not been made, would have manifestly changed the outcome when it was made.” 38 C.F.R. § 20.1403(c). The rule emphasizes that “[i]f it is not absolutely clear that a different result would have ensued, the error cannot be clear and unmistakable.” Id. Rule 1403 also states that “[rjeview for clear and unmistakable error in a prior Board decision must be based on the record ... that existed when that decision was made.” 38 C.F.R. § 20.1403(b)(1).
In Disabled American Veterans v. Gober, 234 F.3d 682 (Fed.Cir.2000), we were called upon to review the validity of the Board's CUE rules under 38 U.S.C. § 502. Among the rules challenged in Disabled American Veterans was Rule 1403(c). It was argued, inter alia, that the rule's outcome determinative requirement was inconsistent with section 7111. We rejected that argument. In so doing, we pointed out that, in section 5109A, "which in relevant part is identical to section 7111, Congress expressly adopted the [Veterans Court's] definition of CUE that requires that 'a claimant must show ... an error would manifestly change the outcome of a prior decision.’ " 234 F.3d at 696 (quoting Bustos, 179 F.3d at 1381).
. At the time Mr. Cook's claim was rejected, the rule of finality codified today in 38 U.S.C. § 7105(c) was set forth in 38 U.S.C. § 709, which stated in relevant part that "[w]hen a *1348claim shall be finally disallowed ..it may not thereafter be reopened or allowed.” Further, the regulations in place at the time stated that "[a] decision of a rating board unap-pealed within one year shall be final.” 38 C.F.R. § 3.330 (1949). Rating boards, under 38 C.F.R. § 3.5 (1949), were vested with the original jurisdiction to determine the issues raised by Mr. Cook of service connection and disability.
. As noted above, the "reversal or revision of a prior decision on the grounds of clear and unmistakable error has the same effect as if the decision had been made on the date of the prior decision.” 38 U.S.C. § 5109A(b).