38 CFR 3.159 establishes the VA's affirmative obligation to assist veterans in gathering evidence and obtaining necessary medical examinations to substantiate their disability claims. Strategic application of this regulation allows advocates to identify procedural errors and secure remands by proving the VA failed to fulfill its statutory development duties.
To prevail at the Board of Veterans' Appeals (BVA) on Duty to Assist (DTA) grounds, practitioners must move beyond the medical merits and focus on the VA's procedural failures during the development phase. The most effective strategy involves demonstrating that the VA failed to obtain 'relevant' records specifically identified by the claimant or that a provided C&P examination was legally inadequate because the examiner failed to consider the veteran’s lay history or ignored pertinent evidence in the claims folder. By highlighting these gaps, attorneys can force a remand under the Appeals Modernization Act (AMA) or legacy systems, effectively resetting the clock and compelling the VA to correct evidentiary deficiencies that led to the initial denial. Success requires a granular review of the record to prove that the veteran met their 'threshold of reliability' while the VA failed its 'duty to develop.' Evidence should include proof of notice, such as a timely filed VA Form 21-4142, or a technical critique of a VA examiner’s rationale that lacks a sufficient 'nexus' explanation. When the BVA finds that the record was not sufficiently developed for a fair adjudication, it is legally required to vacate the underlying decision. This strategy is particularly potent when the missing evidence has a reasonable possibility of changing the outcome, making the DTA error prejudicial to the veteran’s claim.