What evidence wins secondary service connection at the Board

When the Board of Veterans' Appeals decides a secondary service connection claim on the merits, it grants 57.1% of them. For direct claims, it grants 37.6%.

That comes from 260,096 secondary issues and 1,404,026 direct issues that the Board granted, denied or remanded from 2018 to 2026. A secondary claim argues that a service-connected disability caused or worsened another condition (38 CFR 3.310).

Secondary claimsDirect claims

Positive nexus opinion

88.4%

64.2%

Favorable VA exam

82.1%

56.5%

Private medical opinion

70.6%

46.4%

Buddy statement

67.6%

59.0%

Lay statement

52.1%

37.7%

(all claims)

57.1%

37.6%

Issues decided on the merits (granted or denied), 2018 to 2026. Associations, not causes.

The nexus opinion matters most

In secondary claims, the Board granted 88.4% of issues decided on the merits when the record had a positive nexus opinion, and 35.5% when it did not: a gap of 52.9 percentage points. In direct claims the gap was 32.5 percentage points.

A favorable VA exam showed the next largest gap in secondary claims, 31.8 percentage points, followed by a private medical opinion at 26.9 percentage points.

Lay statements alone do not carry secondary claims

Secondary claims with a lay statement in the record were granted less often: 52.1%, compared with 78.6% without one. In direct claims, lay statements made almost no difference (37.7% with, 37.2% without).

This does not mean lay statements hurt. A secondary claim turns on a medical question: did one condition cause or worsen another? Records that lean on lay statements may lack the medical opinion that answers it. Buddy statements, which often describe symptoms seen by others, went with a gap of 10.9 percentage points.

Negative evidence is weighed, not decisive

An unfavorable VA exam or a negative nexus opinion in the record did not end secondary claims. The Board still granted 54.3% of merits decisions with an unfavorable VA exam and 52.6% with a negative nexus opinion. The Board weighs all the evidence and resolves reasonable doubt in the veteran's favor (38 CFR 3.102).

For representatives

• Treat the nexus opinion as the center of a secondary claim. Ask it to address both causation and aggravation under 38 CFR 3.310.
• A lay statement supports the timeline and symptoms, but it does not replace a medical opinion on the link between the conditions.

These are associations across many decisions, not proof that one piece of evidence caused a result. Evidence is recorded per decision, so a decision with several issues counts its evidence for each of them.