What is a nexus letter? (and what it needs to say)

A nexus letter is a signed opinion from a medical provider connecting your condition to your service — or to another service-connected condition. It is often the piece that decides a claim.

The magic phrase

Raters look for the standard of proof in plain words: that your condition is "at least as likely as not" (a 50% or greater probability) caused or aggravated by your service, or by your service-connected [primary condition]. A letter that hedges below that ("possibly," "could be") usually isn't enough.

What a strong nexus letter includes

• Who the provider is and that they reviewed your history/records.
• Your diagnosis.
• The "at least as likely as not" opinion, with a short rationale — the medical reasoning for the link.
• A signature and credentials.

Who writes it

Your treating provider, a private doctor, or a specialist. A one-time C&P contract examiner evaluates you for the VA — they are not your treating provider and generally won't write your nexus or work forms; use your own provider for that.