Most VA claims are decided on evidence — not justice, not advocacy, and not how deserving the veteran is. The VA adjudicator sitting behind a claims file evaluates what's in the record against a legal standard. Understanding the five types of evidence the VA is legally required to consider, how each type is weighted, and what you need to do to ensure each one is in your file is the difference between a claim that wins and one that languishes for years. This guide explains all five, with the CFR citations that govern them and the 2025 strategy for building the strongest possible evidence package.
Two regulations form the foundation of how the VA evaluates claims evidence. Every veteran filing a disability claim should understand both.
38 CFR § 3.303 — Principles Relating to Service Connection sets out the general rule that service connection requires (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a nexus between the current disability and the in-service event. Section 3.303 also establishes that both medical evidence and competent lay evidence are legitimate bases for service connection — the regulation does not privilege one over the other in all circumstances.
38 CFR § 3.102 — Benefit of the Doubt establishes the evidentiary standard the VA uses when making decisions. When there is an approximate balance of positive and negative evidence — when the case is roughly 50/50 — the VA must resolve the reasonable doubt in favor of the veteran. This is a lower threshold than the "preponderance of evidence" standard used in civil courts, and it's a deliberate policy choice reflecting Congress's intent to protect those who served.
Together, these two regulations create a system in which a veteran who builds a balanced, multi-source evidence package — even without a single piece of conclusive proof — can and should win their claim.
You do not need to prove your claim is more likely than not true. You need to show the evidence is roughly equal — and if it is, 38 CFR 3.102 requires the VA to decide in your favor. A well-assembled evidence package makes that balance achievable.
The benefit of the doubt doctrine is one of the most veteran-favorable standards in American administrative law — and one of the least understood. It means that unlike a plaintiff in civil court who must show their version of events is more likely to be true (51%+ probability), a veteran only needs to bring the evidentiary scale to approximate balance. At 50/50, the veteran wins.
This standard was established in Gilbert v. Derwinski, 1 Vet.App. 49 (1990), where the CAVC held that the VA must resolve the benefit of the doubt in favor of the claimant when there is an "approximate balance of positive and negative evidence." The court also held that the benefit of the doubt applies not just to medical questions but to all factual disputes in the claim — including in-service events, continuity of symptomatology, and credibility of lay testimony.
The practical implication: if you submit a private nexus letter that says the condition is "at least as likely as not" service-connected, and the VA's C&P exam says it's "less likely than not," you now have roughly balanced medical opinions. The benefit of the doubt must be applied in your favor. A denial after that would be legally improper and an appropriate basis for appeal.
STRs are the in-service medical records created during your active duty service — sick call visits, physical exam results, injury reports, mental health notes, and any medical documentation generated at military treatment facilities. These are the gold standard of VA claims evidence because they document what happened to you while you were actually serving.
How to get them: Request STRs through the National Personnel Records Center (NPRC) at vetrecs.archives.gov, by submitting Standard Form 180 (SF-180), or through your MyHealtheVet account if records have been digitized. If you're currently filing through eBenefits or VA.gov, the VA is supposed to request your STRs under the duty to assist — but don't rely on this. Request them yourself so you know what's in the file.
What if records are missing or destroyed? The 1973 NPRC fire in St. Louis destroyed records for approximately 16–18 million Army and Air Force veterans who were discharged between November 1912 and January 1960. If your records were affected, the VA must assist you in reconstructing them under 38 CFR § 3.159(c)(3). Alternative sources include unit diaries, morning reports, buddy statements, and personnel files. If the VA denies a claim citing insufficient in-service evidence and your records were potentially destroyed in the fire, you can raise this at any appeal stage.
Post-service treatment records from VA facilities — VA hospitals, VA community-based outpatient clinics (CBOCs), and VA-referred community care providers — are the second type of evidence the VA must consider. Unlike private medical records, VA medical records are automatically part of your claims file. The VA is legally required under 38 CFR § 3.159(c)(2) to retrieve these records from its own facilities without you needing to request or submit them.
This automatic retrieval is significant: if you've been treated at a VA facility for your claimed condition, those treatment notes, diagnostic results, and provider opinions are already supporting your claim whether or not you actively submit them. Make sure you're actually using VA healthcare for your claimed conditions — each visit creates documentation that builds your evidence file.
Strategic note: Regular VA treatment for a claimed condition creates a documented history of ongoing symptoms and functional impact that supports both service connection and a higher disability rating. Gaps in VA treatment can be used by raters to question severity — consistent treatment creates consistent documentation.
Private medical records — from civilian physicians, specialists, hospitals, and mental health providers — are the third type of evidence the VA must consider. Unlike VA records, private records are not automatically retrieved. Under 38 CFR § 3.159(c)(1), the VA will attempt to obtain private records only if you authorize the release and the records are reasonably accessible. In practice, this means you need to submit your private records yourself or authorize VA to request them with a specific, signed release.
This is one of the biggest errors veterans make: assuming the VA will gather all their records. They won't. If you have private specialist evaluations, diagnoses, imaging studies, or treatment records that support your claim — submit them. Every medical record that isn't in your file is evidence the VA doesn't have to consider.
Most importantly: private medical records are the vehicle for delivering your private nexus letter — the opinion from a non-VA provider connecting your diagnosis to service. Without submitting it yourself, it isn't in the file.
Editorial Standards: This article was written by Marcus J. Webb, a veterans benefits researcher who has studied 38 CFR Part 4, the VA M21-1 Adjudication Manual, and thousands of BVA decisions. Content is verified against current 38 CFR regulations and VA.gov guidance. Last reviewed: April 2026. Not legal advice — for representation on your specific claim, talk to a VA-accredited attorney.