Nexus letter template: a fill-in-the-blank sample for any VA claim, direct or secondary

Reviewed by Jonathan Teplitsky · Updated August 2026

What a nexus letter template must contain to be effective

A strong nexus letter needs five things: the provider's credentials, proof they reviewed your records, a clear diagnosis, a medical rationale, and the "at least as likely as not" conclusion. This page gives you one fill-in-the-blank template that works for any condition, plus swap-in notes for nine common claims. If your condition is sleep apnea, PTSD, or depression, use the dedicated template instead. Those pages already have condition-specific language built in. Before you start, it helps to understand what a nexus letter is and how it fits with a DBQ. For the full walkthrough of getting one written, see the nexus letter guide.

Direct versus secondary claims

A nexus letter connects a diagnosed condition to a cause. VA recognizes two paths for that connection. A direct claim ties your condition to something that happened in service, such as an injury, an exposure, or a documented in-service event. A secondary claim ties your condition to another disability VA has already rated.

Chronic pain, PTSD, and sleep apnea are common root conditions. They cause or worsen other health problems years after the original diagnosis. Most veterans qualify under one path or the other. Some conditions, like migraines or anxiety, can go either way depending on your individual history.

The 5 elements of a strong nexus letter

• Credentials. The provider's name, license, and specialty, and why they are qualified to give this opinion.
• Records reviewed. A statement that they reviewed your service treatment records, VA medical records, or claims file, not just one office visit.
• Diagnosis. The exact condition and its diagnostic code, stated in medical terms.
• Rationale. The "because." This is the medical reasoning that explains why the connection exists, and it carries the most weight of any section.
• Conclusion. The "at least as likely as not" opinion stating the link in plain language.

The "at least as likely as not" standard

VA does not require certainty. Service connection only needs a probability of 50% or greater, phrased as "at least as likely as not." Under 38 CFR 3.102, when the evidence is roughly balanced, VA must resolve that tie in the veteran's favor.

That is why the exact phrase matters so much on this kind of form. Softer wording like "could be related" or "possibly linked" falls short of the standard. That kind of language gives a rater an easy reason to deny the claim.

Weight tip: A conclusion sentence with no reasoning behind it carries little weight. The rationale, the paragraph explaining the medical mechanism, is what makes a rater or the Board take the opinion seriously.

Fill-in-the-blank nexus letter template

Copy the version that fits your claim and replace every [bracketed] placeholder. Then have your provider review, complete, and sign it on their own letterhead. Both versions below work for any diagnosed condition, not just the nine covered on this page.

Secondary claim (most common for chronic conditions)

[Provider Name], [Credentials/License] · [Clinic / Address] · [Date]

RE: [Veteran Name], [VA File Number / SSN]

I am a [physician / specialist / nurse practitioner] licensed in [State], with [X] years treating [relevant field]. I have reviewed [Veteran]'s service treatment records, VA medical records, and claims file (C-file).

[Veteran] is diagnosed with [condition name] per [diagnostic criteria or testing]. [Veteran] is service-connected for [primary condition] at [XX]%.

It is my professional medical opinion that [Veteran]'s [condition] is at least as likely as not (50% or greater probability) caused by, or alternatively aggravated beyond its natural progression by, the service-connected [primary condition].

Rationale: [Explain the medical mechanism connecting the two conditions, the timeline shown in the records, and any supporting literature.]

Sincerely, [Signature] · [Provider Name, Credentials]

Direct service connection

[Same header and credentials block as above.]

It is my professional medical opinion that [Veteran]'s [condition name] is at least as likely as not (50% or greater probability) related to [his/her] active military service.

Rationale: [Tie the condition to a specific in-service event, exposure, or documented symptom. Note whether symptoms have been continuous since service and whether the current clinical picture is consistent with that onset.]

Sincerely, [Signature] · [Provider Name, Credentials]

Swap in your specific condition

Each condition below has a typical connection pattern. Use it as a starting point for the rationale section of the template above. These are general patterns based on common claim outcomes, not guarantees. Your provider decides what actually applies to your own medical history.

• Tinnitus. Commonly a direct claim tied to noise exposure in service, since tinnitus and hearing loss share the same underlying cochlear-damage mechanism. It is also filed secondary to service-connected hearing loss or the same in-service noise event.
• Back pain. Usually direct, tied to a documented in-service injury, heavy lifting, or repetitive strain, especially when symptoms have been continuous since separation. It can also be filed secondary to an altered gait caused by a service-connected leg or foot condition.
• GERD. Frequently secondary to long-term NSAID use for a service-connected musculoskeletal condition like a back, knee, or shoulder injury. NSAIDs erode the stomach lining and increase acid production, a well-documented mechanism that providers can cite directly.
• IBS. Often secondary to chronic stress and hyperarousal from service-connected PTSD or anxiety, both of which can disrupt normal gut function. Gulf War veterans should also check whether IBS qualifies as a presumptive condition before pursuing a secondary nexus letter instead.
• Hypertension. Commonly secondary to service-connected sleep apnea, since disrupted breathing during sleep is linked to elevated blood pressure over time. It is also filed secondary to PTSD, given the documented physical effects of chronic stress.
• Hearing loss. Typically a direct claim from noise exposure to gunfire, aircraft, or heavy equipment during service. It often pairs with a tinnitus claim tied to that same exposure event.
• Migraines. Can be direct, tied to a documented head injury or TBI from service, or secondary to a service-connected cervical spine condition or PTSD, both of which are recognized migraine triggers.
• Anxiety. Often secondary to a service-connected physical condition that limits daily function, or to PTSD itself. It can also be filed as a direct claim tied to a specific in-service stressor.
• Jet fuel exposure conditions. Check the PACT Act presumptive conditions list first. If your diagnosed condition is on that list, and your service location and dates qualify, VA presumes service connection automatically. You may not need a nexus letter at all for a presumptive condition. Save the letter for conditions the presumption does not cover.

Who can write it

The opinion must come from a qualified medical provider. That is typically a physician, a specialist in the relevant field, or in many cases a nurse practitioner or physician assistant. It can be your treating provider or an independent provider you hire specifically for the claim.

A statement you write yourself about your own symptoms is useful as a lay statement. It cannot replace a provider's signed medical opinion, no matter how detailed your own account is.

How to use this template with your provider

Fill in every bracket before your appointment. A provider who receives a half-blank template has to do more work, and rushed work produces weaker rationale sections.

Bring your service treatment records, current diagnosis paperwork, and a short timeline of your symptoms. List any prior C&P exam results too. The more organized evidence your provider has in front of them, the more specific and defensible the rationale paragraph will be.

Ask your provider to read the finished letter out loud before signing. A rationale that sounds vague when read aloud usually reads as vague to a rater too.

Common mistakes that sink nexus letters

• Using soft language like "could be" or "may be linked" instead of "at least as likely as not."
• Stating the conclusion with no rationale behind it. The reasoning is what gives an opinion its weight.
• No statement that the provider reviewed your records or claims file before writing the opinion.
• Forgetting the aggravation path. A service-connected condition can worsen an existing problem even without causing it outright.
• Filing a nexus letter for a PACT Act presumptive condition when none is required.
• An unsigned letter, or one signed by the veteran instead of a licensed provider.

Important: This is an educational template, not legal or medical advice. The nexus letter must be completed, reviewed, and signed by a qualified medical provider. For help after a denial, see whether you need a VA appeals attorney.