Claim Raven explanation
What this means
Clear and unmistakable error is a specific, rare error that would have made the result manifestly different. Review generally uses the facts and law that existed when the Board made the decision.
A disagreement over how evidence was weighed is not CUE. The rule also describes other examples that do not qualify, including a later changed diagnosis and a failure in the duty to assist.
How this helps your claim
Test the proposed error against the actual old record and legal standard before choosing this route. Explain why the outcome would necessarily have changed, rather than why a different result was merely possible.
What to check in your records
Use your decision, examination reports, and relevant records to check the following points.
- Obtain the evidence and law applicable at the time of the Board decision.
- Identify a specific factual or legal error beyond disagreement about weighing evidence.
- Explain how correcting that error would have required a different outcome.
Identify the alleged error in the historical record
CUE review generally asks about the facts and law when the Board decided the matter. A later medical development or new interpretation of the evidence does not automatically establish that the old decision contained the required rare error.
State what was wrong and why correcting it would have made the outcome manifestly different. Keep that explanation separate from ordinary disagreement over how evidence was weighed. The regulation's examples of what is not CUE help prevent a general dissatisfaction from being mislabeled as this particular challenge.
Is a failure to obtain records automatically Board CUE?
No. The rule identifies failure in the duty to assist as an example that does not qualify. That does not mean the concern is unimportant; it means CUE has a specific scope. Different review mechanisms address different kinds of errors and should not be treated as substitutes for one another.
Official regulatory text
38 CFR § 20.1403
eCFR snapshot: September 3, 2026. Layout and spacing are adapted for reading. The full section and its tables are included below.
§ 20.1403 Rule 1403. What constitutes clear and unmistakable error; what does not.
(a) General. 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. Generally, either the correct facts, as they were known at the time, were not before the Board, or the statutory and regulatory provisions extant at the time were incorrectly applied.
(b) Record to be reviewed —
(1) General. Review for clear and unmistakable error in a prior Board decision must be based on the record and the law that existed when that decision was made.
(2) Special rule for Board decisions on legacy appeals issued on or after July 21, 1992. For a Board decision on a legacy appeal as defined in § 19.2 of this chapter issued on or after July 21, 1992, the record that existed when that decision was made includes relevant documents possessed by the Department of Veterans Affairs not later than 90 days before such record was transferred to the Board for review in reaching that decision, provided that the documents could reasonably be expected to be part of the record.
(c) Errors that constitute clear and unmistakable error. To warrant revision of a Board decision on the grounds of clear and unmistakable error, 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. If it is not absolutely clear that a different result would have ensued, the error complained of cannot be clear and unmistakable.
(d) Examples of situations that are not clear and unmistakable error —
(1) Changed diagnosis. A new medical diagnosis that “corrects” an earlier diagnosis considered in a Board decision.
(2) Duty to assist. The Secretary's failure to fulfill the duty to assist.
(3) Evaluation of evidence. A disagreement as to how the facts were weighed or evaluated.
(e) Change in interpretation. Clear and unmistakable error does not include the otherwise correct application of a statute or regulation where, subsequent to the Board decision challenged, there has been a change in the interpretation of the statute or regulation.
(Authority: 38 U.S.C. 501(a), 7111)
[57 FR 4109, Feb. 3, 1992, as amended at 84 FR 192, Jan. 18, 2019]
Related references
- 38 CFR § 19.2: Legacy Appeals and Opting Into Modernized Review
- 38 CFR § 3.2400: Modernized and Legacy VA Appeals Explained
- 38 CFR § 3.159: VA duty to assist: records and examinations
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