Written by Dr. Ryan, DO
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Free Viability Check →Yes, you can write your own statement and send it to the VA. Nothing stops you. The problem is weight. VA rules sort evidence by who it comes from, and a nexus opinion (the part that says your condition was caused by your service, or by another service-connected condition) is a medical question. When you write it yourself, or have ChatGPT write it and sign it yourself, the VA treats it as lay evidence, no matter how polished it reads. For most conditions, that means it gets little weight against a C&P examiner's opinion.
Key facts
Veterans are doing it. Reddit threads about it. There are even websites now that will generate a "nexus letter" from AI for free. Upload your records, get a letter, take it to your doctor to sign.
It sounds like it should work. The AI can cite medical literature. It can use the right legal phrases. It can produce something that looks exactly like the nexus letters that cost $800 to $1,500.
But looking like a nexus letter and surviving VA scrutiny are different things, which comes down to what makes a nexus letter strong in the first place.
We analyzed 295,756 Board of Veterans Appeals decisions from 2021 through 2025 to understand what makes medical opinions succeed or fail. The data is clear on what the BVA values and what it throws out.
38 CFR 3.159 defines two kinds of evidence. Competent medical evidence comes from “a person who is qualified through education, training, or experience to offer medical diagnoses, statements, or opinions.” Competent lay evidence covers “matters that can be observed and described by a lay person.”
You are fully competent to describe what you saw and felt: when your knee started hurting, that you started snoring after deployment, that your ears rang after the range. Whether one condition caused another is usually a medical question, and that is the question a nexus letter answers.
The VA's own claims manual says it plainly: “A medically-untrained individual is not usually competent to offer a medical opinion regarding the etiology of disorders and such an opinion is generally assigned little probative weight” (M21-1, Part V, Subpart ii, Chapter 1, Section B). A letter written by ChatGPT does not change this. The VA looks at who is giving the opinion, not how it was typed.
The Board applies this constantly. A typical line from a decision: the veteran “is not competent to ascertain the etiology of any current condition, as the causative factors for such are not readily subject to lay observation.”
Medical articles do count as medical evidence under 38 CFR 3.159. But the Veterans Court has held that general medical literature, on its own, is usually “too general and inconclusive” to connect a condition to one particular veteran, and that it gives important support when combined with the opinion of a medical professional (Sacks v. West, 1998). That is the gap in a self-written letter: the studies may be real, but nobody qualified has applied them to your record.
No. The VA may presume its examiner is competent (Rizzo v. Shinseki, Fed. Cir. 2009), but the weight of any medical opinion, VA or private, comes from its reasoning. In Nieves-Rodriguez v. Peake (2008), the Veterans Court wrote that “most of the probative value of a medical opinion comes from its reasoning,” and that an opinion that “contains only data and conclusions” is not entitled to any weight. A weak C&P opinion can lose to a well-reasoned private medical opinion. It usually does not lose to a lay statement.
Sometimes, for simple conditions. The Federal Circuit has held that lay evidence can be competent when “a layperson is competent to identify the medical condition” (Jandreau v. Nicholson, 2007), and that the VA cannot reject lay evidence on the cause of a condition just because it comes from a layperson (Davidson v. Shinseki, 2009). The VA decides case by case whether your condition is the kind lay evidence can speak to (Kahana v. Shinseki, 2011).
In practice: “I broke my ankle on a jump and it has hurt ever since” can stand on your own word. “My PTSD caused my sleep apnea” or “burn pits caused my high blood pressure” cannot. Those are medical cause-and-effect questions.
The VA cannot fill the gap with its own medical judgment. It has to rely on independent medical evidence (Colvin v. Derwinski, as applied in Kahana). So the usual result is another exam or an addendum opinion, not a grant. The benefit of the doubt in 38 U.S.C. 5107(b) applies only when the evidence is in “approximate balance,” and a lay opinion on a medical question rarely creates that balance.
The BVA's word, not ours. A "conclusory" opinion states a conclusion without explaining why. "It is my opinion that this condition is related to service" with no specific reasoning tied to the veteran's actual records.
AI is good at generating confident-sounding conclusions. It's bad at building reasoning from specific clinical findings in specific records it hasn't actually reviewed. The BVA threw out opinions for being "conclusory" hundreds of times in our dataset.
"Could have been caused by," "may be related to," "it is possible that." These phrases appear constantly in AI output because AI hedges by default. The BVA specifically flags these as reducing probative weight. Warren v. Brown established that "could have been" language is not probative. Tirpak v. Derwinski said the same about "may or may not."
In our analysis, "speculative" was the third most common reason the BVA rated a medical opinion as not probative.
Two more reasons show up again and again in the Board's own language: the opinion did not consider contrary evidence (it never addressed other possible causes or the findings that cut against it), and the author did not review the file. A letter that fails these tests is not neutral. When the Board explicitly rejects an opinion, that rejection can end up strengthening the denial.
This is the big one. A nexus letter requires a licensed medical professional to review the veteran's actual records, form an independent medical opinion, and sign it. Under Nieves-Rodriguez v. Peake, the BVA evaluates three things: was it factually accurate, was the reasoning fully articulated, and was it based on sound medical principles applied to this specific veteran?
AI can produce the format. It cannot review records, form a medical opinion, or take professional responsibility for the conclusion. If a veteran submits an unsigned AI letter, it's a lay statement. If a physician signs an AI letter they didn't actually review, they're putting their license behind reasoning they didn't develop from records they didn't read.
To be fair, AI isn't useless in the claims process. It can help you organize your thoughts for a personal statement. It can help you understand medical terminology in your records. It can give you a rough sense of whether your condition might qualify for secondary service connection. As a research and drafting tool for lay statements, it has real value.
And if you use AI to draft something and then take it to your own doctor who genuinely reviews your records, edits the reasoning, and signs it as their own opinion, that can work. At that point your doctor is doing the medical work. The AI helped with formatting. That's a legitimate use.
But submitting an AI-generated letter on its own, unsigned, or rubber-stamped by a provider who didn't actually review your records? There is zero data in 295,756 BVA decisions that suggests this helps your claim. None. We looked.
Where your own writing does carry real weight: your personal statement (when symptoms started, how they changed, how they affect work and life), buddy statements from people who saw it, and a clear timeline of your records so the physician can find what matters. You are the best witness to all of that.
You can write your own nexus letter, and the VA will read it. But on the medical question of what caused your condition, VA rules give it little weight. For a medical opinion to carry weight at the VA, a licensed physician has to sign it. That's not a technicality. It's the whole point. The BVA evaluates whether a qualified medical professional reviewed your specific records and explained, with sound reasoning, why your condition is connected to your service.
AI can help you prepare. It cannot replace the physician. The reasoning has to come from your records. The signature has to mean something. And right now, there is no evidence that AI-generated nexus letters improve outcomes at the Board of Veterans Appeals.
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