A nexus letter is not a strict legal requirement to file a claim, but it serves an important evidentiary function. To establish service connection — including secondary service connection under 38 CFR 3.310 — you generally need three things: a current diagnosis, an in-service event, injury, or a service-connected condition that could cause or aggravate the claimed condition, and medical evidence linking the two (the "nexus"). A private nexus letter from a treating physician is simply one common way to satisfy that third element, but it is not the only way.
You can submit medical literature, such as peer-reviewed studies showing a recognized link between conditions (for example, rhinitis and sleep apnea), as part of your evidence package. VA adjudicators and the C&P examiners who evaluate your claim are supposed to consider this literature, though it is often more persuasive when a medical professional applies it specifically to your case rather than being submitted as a standalone article. Filing without a signed nexus letter is possible, and the VA has a duty to assist that includes scheduling a Compensation and Pension exam when the evidence suggests a plausible link but is not fully developed. The C&P examiner can review the record, including any medical literature you submit, and render their own opinion on the nexus question.
Official 2026 VA monthly compensation, including the 2.8% COLA increase.
Dependent add-ons start at a 30% rating. Child-only and dependent-parent rates: see the full 2026 pay chart.
| Rating | Monthly (2026, incl. 2.8% COLA) |
|---|---|
| 10% | $180.42 |
| 20% | $356.66 |
| 30% | $552.47 |
| 40% | $795.84 |
| 50% | $1,132.90 |
| 60% | $1,435.02 |
| 70% | $1,808.45 |
| 80% | $2,102.15 |
| 90% | $2,362.30 |
| 100% | $3,938.58 |
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Analyze my claim free →That said, outcomes on secondary service connection claims vary widely, and evidence quality matters. In the appealed VA decisions in VetAid's library, among service connection cases with a recorded appellate disposition, half were vacated or remanded, about a third were affirmed with the denial standing, and a small share were reversed or granted outright — a reminder that these figures describe appeals outcomes, not the odds of an initial claim being approved, and that appealed cases are not representative of all claims filed. If you can eventually find another provider, including a telehealth nexus letter service, that reviews your records and offers a reasoned opinion connecting the conditions, it will generally strengthen your file considerably.
As a next step, submit your claim with the supporting medical literature and any private treatment records you have, and consider requesting a formal C&P exam or seeking a nexus opinion from another qualified provider while the claim is pending.
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