38 CFR 20.203: Rule 203. Place and time of filing of Notice of Disagreement.

(a) Place of filing. The Notice of Disagreement must be filed with the Board of Veterans' Appeals, P.O. Box 27063, Washington, DC 20038.

(b) Time of filing. Except as provided in § 20.402 for simultaneously contested claims, a claimant, or his or her representative, must file a properly completed Notice of Disagreement with a decision by the agency of original jurisdiction within one year from the date that the agency mails the notice of the decision. The date of mailing the letter of notification of the decision will be presumed to be the same as the date of that letter for purposes of determining whether an appeal has been timely filed.

(c) Extension of time of filing. An extension of the period for filing a Notice of Disagreement or a request to modify a Notice of Disagreement may be granted for good cause. A request for such an extension must be in writing and must be filed with the Board. Whether good cause for an extension has been established will be determined by the Board.