38 C.F.R. § 3.160
(a) Complete claim. A submission of an application form prescribed by the Secretary, whether paper or electronic, that meets the following requirements:
(d) Finally adjudicated claim. A claim that is adjudicated by the Department of Veterans Affairs as either allowed or disallowed is considered finally adjudicated when:
(1) For legacy claims not subject to the modernized review system, whichever of the following occurs first:
(e) Reopened claims prior to effective date of modernized review system. An application for a benefit received prior to the effective date provided in § 19.2(a) of this chapter, after final disallowance of an earlier claim that is subject to readjudication on the merits based on receipt of new and material evidence related to the finally adjudicated claim, or any claim based on additional evidence or a request for a personal hearing submitted more than 90 days following notification to the appellant of the certification of an appeal and transfer of applicable records to the Board of Veterans' Appeals which was not considered by the Board in its decision and was referred to the agency of original jurisdiction for consideration as provided in § 20.1304(b)(1) of this chapter. As of the effective date provided in § 19.2(a) of this chapter, claimants may no longer file to reopen a claim, but may file a supplemental claim as prescribed in § 3.2501 to apply for a previously disallowed benefit. A request to reopen a finally decided claim that has not been adjudicated as of the effective date will be processed as a supplemental claim subject to the modernized review system.
(Authority: 38 U.S.C. 501)
[27 FR 11887, Dec. 1, 1962, as amended at 31 FR 12056, Sept. 15, 1966; 55 FR 20148, May 15, 1990; 58 FR 32445, June 10, 1993; 79 FR 57696, Sept. 25, 2014; 84 FR 170, Jan. 18, 2019]