38 CFR §21.416

1. (a)Applicability. This section applies where notice of a decision under this subpart or subpart M of this part was provided to a claimant or his/her representative on or after the effective date of the modernized review system as provided in § 19.2(a) of this chapter, or where a claimant has elected review of a legacy claim under the modernized review system as provided in § 3.2400(c) of this chapter.
2. (b)Reviews available. Within one year from the date on which VA issues notice of a decision on an issue contained within a claim, a claimant may elect one of the following administrative review options:
   1. (1)Supplemental Claim. The nature of this review will accord with § 3.2501 of this chapter, except that a complete application in writing on a form prescribed by the Secretary will not be required and a hearing will not be provided.
   2. (2)Appeal to the Board of Veterans' Appeals. See 38 CFR part 20.
   3. (3)Higher-level Review. The nature of this review will accord with § 3.2601.
3. (c)Notice requirements. Notice of a decision made under paragraph (b)(1) or (3) of this section will include all of the elements described in § 21.420(b).