Nexus Letters: The Key to Winning Your VA Claim

What Is a Nexus Letter?

A nexus letter is a written medical opinion from a qualified healthcare provider that establishes a connection (“nexus”) between your current medical condition and your military service. It is the critical bridge between your diagnosis and your service connection.

The VA requires that this connection be stated in terms of probability. The standard language is: “It is at least as likely as not (50% or greater probability) that [condition] is caused by / related to [in-service event/condition].”

Without a nexus letter, the VA may deny your claim even if you clearly have a diagnosed condition and documented in-service events. The nexus letter provides the medical reasoning connecting the two.

Who Can Write a Nexus Letter?

A nexus letter must be written by a competent medical professional qualified to opine on the specific condition. This includes:

• Medical Doctors (MD/DO) — Carry the most weight, especially specialists in the relevant field
• Nurse Practitioners (NP) — Accepted by the VA, though specialist MDs carry more weight
• Physician Assistants (PA) — Accepted when practicing within their scope
• Psychologists (PhD/PsyD) — For mental health conditions like PTSD
• Licensed Clinical Social Workers (LCSW) — For mental health nexus opinions, though psychologists and psychiatrists carry more weight

The provider does not need to be your treating physician, though a letter from a long-term treating provider who knows your history well can be very persuasive.

What Makes a Strong Nexus Letter

Not all nexus letters are created equal. The VA weighs medical opinions based on their thoroughness and reasoning. A strong nexus letter includes:

1. Provider credentials — Full name, credentials, license number, specialty, and years of experience
2. Review of records — The provider should state they reviewed your service treatment records, post-service medical records, and any relevant documentation
3. Medical history summary — A thorough discussion of your condition, when it began, and how it has progressed
4. In-service connection — A clear explanation of the in-service event, injury, or exposure and how it relates to the current condition
5. Medical reasoning (rationale) — This is the most important part. The provider must explain why your condition is connected to service, citing medical literature, clinical experience, and the specific facts of your case
6. The nexus statement — Using the required language: “at least as likely as not”
7. Consideration of alternative causes — Addressing and ruling out other possible causes strengthens the opinion

IMO vs. IME

Independent Medical Opinion (IMO): A written opinion based on record review. This is what most “nexus letters” are — the provider reviews your records and provides their medical opinion without necessarily examining you in person.

Independent Medical Examination (IME): The provider conducts an in-person examination in addition to reviewing records. IMEs carry more weight because the examiner has directly observed your condition.

When possible, an IME is preferable, but a well-reasoned IMO with thorough record review is often sufficient.

Common Nexus Letter Mistakes

• Conclusory opinions — Simply stating the nexus without explaining why (no rationale)
• Wrong probability language — Using “possibly” or “could be” instead of “at least as likely as not”
• Not reviewing records — Opinions without a record review carry significantly less weight
• Unqualified provider — A podiatrist writing a nexus for PTSD, or a provider opining outside their expertise
• Too short — One-paragraph letters without medical reasoning are easily dismissed

How to Get a Nexus Letter

• Ask your treating physician. If you have a good relationship with a doctor who understands your condition and service history, ask them to write a nexus letter.
• Use a nexus letter service. There are medical providers who specialize in writing nexus letters for veterans. Make sure they provide thorough, individualized opinions (not templates).
• VA doctors. VA providers can write nexus letters, though they sometimes decline. You have the right to request one.
• Organize your evidence first. Before requesting a nexus letter, organize your medical records, service records, and any supporting evidence using our Document Vault. The better organized your records, the stronger the nexus letter will be.