VA Nexus Letters: Why They Matter for Disability Claims
Many veterans run into the same frustrating problem when it comes to VA nexus letters. They know it’s one of the most important pieces of evidence for a VA disability claim, but getting one feels confusing and overwhelming.
Who writes it? What should it say? And why do so many claims get denied even after a veteran submits a letter?
The truth is, most veterans don’t fully understand what makes a nexus letter strong in the eyes of the VA.
Without the right medical evidence, clear language, and professional backing, the letter can be dismissed or carry little weight. This leads to delays, denials, and veterans feeling stuck in the claims process.
That’s where this guide comes in. We’ll break down everything you need to know about nexus letters. We will cover what they are, why they matter, who can write them, and how to make sure yours gives you the best chance at a successful claim.
What is a Nexus Letter?
A nexus letter is a written medical opinion from a licensed healthcare provider that connects your current disability to your military service — or to another service-connected condition.
In plain terms, it’s a doctor saying:
“It’s at least as likely as not that this veteran’s condition was caused or aggravated by their service.”
You don’t need to prove the connection with 100% certainty — just show there’s an equal or greater chance that service played a role.
What the VA Requires for a Medical Nexus
A strong nexus letter must:
Be written by a qualified medical professional (MD, DO, NP, or psychologist).
Include clear medical reasoning, not just a statement of belief.
Use VA language such as “at least as likely as not” (50% or greater probability).
Reference the evidence reviewed — service records, medical files, or exams.
Example:
If a veteran develops PTSD after a documented in-service trauma, the nexus letter should explain how and why that trauma is just as likely to have caused the PTSD as any other factor.
Nexus Letter vs. Nexus Statement: What’s the Difference?
Both show that your condition is service-related — the difference is in depth and detail.
Nexus Letter:
Full medical opinion from a doctor.
Includes diagnosis, medical history, and rationale.
Carries more weight because it’s evidence-based.
Nexus Statement:
Brief summary that mentions a possible link.
Lacks detailed explanation or supporting evidence.
May help, but rarely changes a tough claim on its own.
Always clarify what your provider is giving you — the VA values a detailed, medically reasoned letter far more than a one-paragraph statement.
Where the Nexus Letter Fits For Your VA Claim
To win a VA disability claim, you must prove three things:
Current Diagnosis – A verified medical condition.
In-Service Event or Injury – Something that happened during service.
Medical Nexus – A doctor’s opinion linking the two.
That third element — the nexus — is what this letter provides. Without it, the VA usually can’t grant service connection.
Who Can Write Your Nexus Letter?
Any licensed medical provider can write a nexus letter, but the VA gives more weight to doctors who provide detailed, well-reasoned medical explanations.
You’ve probably heard people say a nexus letter only “counts” if it comes from a certain type of doctor, but no single provider is the best choice for every claim.
The key is understanding what your specific claim requires and choosing the doctor whose expertise fits those needs
Best Types of Providers for a Strong Nexus Letter
Primary Care Provider: A good starting point since they already know your medical history. They offer decent credibility and are often easier to reach locally, especially if you’ve had a long, consistent relationship with them.
Nurse Practitioner – While their opinions carry less weight with the VA, they’re typically more accessible and can still help by verifying ongoing symptoms or treatment. These nexus letter work best as supporting evidence.
Specialist – Brings high medical credibility and is often necessary for complex or secondary conditions. Specialists can clearly explain how one condition caused or worsened another, though they may be more expensive.
Veterans Service Organizations (VSOs) – VSOs can’t write nexus letters, but they’re one of the best free starting points. They can guide you toward reputable doctors and explain what kind of letter you need.
Paid Companies – These are easy to access but vary greatly in credibility and quality. They usually have a good understanding of VA language, but are prone to using generic templates. You should only hire a company as a last resort.
In the end, the best source for a nexus letter depends on your specific condition and the doctors available to you.
Obtaining a Nexus Letter (Brief Overview)
Getting a nexus letter from a doctor is usually easier said than done. There are many right and wrong ways to go about it, and most doctors aren’t familiar with VA requirements.
The key is doing your own research, understanding your condition, and preparing your records in a way that takes as much work off the doctor as possible.
Most veterans start by asking their VA or civilian provider, but if that doesn’t work, they often get recommendations from a VSO or look for specialists online.
As a last resort, consider reputable paid companies that handle disability evaluations.
What Your Nexus Letter Must Include
A strong nexus letter must clearly explain the diagnosis, evidence reviewed, and medical reasoning behind the service connection. The VA prioritizes clarity, detail, and credible documentation.
Here is a good checklist to follow:
Doctor Credentials – Include the doctor’s name, specialty, board certifications, and ideally a CV to show credibility.
Evidence Reviewed – The doctor should address all records including denials, failed C&P exams, and any other evidence mentioned.
Diagnosis – Clearly state a medical condition the patient has and how they reached that conclusion, including tests, exams, and medical literature if relevant.
Medical Reasoning – The most important part. The doctor should clearly explain why the condition is related to military service, reference medical literature, and rule out other likely causes.
VA Language – Use VA-specific language, like: “It is at least as likely as not (50% or greater probability) that the veteran’s condition is related to military service.”
Signature & Contact – The letter must be signed with full credentials and include contact information for follow-up if the VA needs clarification.
Later, I will show real examples and what applying this information looks like in practice.
What Your Nexus Letter Should Actually Say
Your doctor should open the nexus letter by stating who they are and how they know you. After that, they should give their medical opinion and clearly explain the reasoning behind it.
How A Basic Letter Reads
I am [Doctor Name, Credentials]. I evaluated [Veteran Name] and reviewed their [service treatment records, medical history, prior evaluations, and reported symptoms]. From this review and my clinical examination, I confirmed the diagnosis of [Diagnosis].
Once the diagnosis and timeline were established, I assessed possible causes. Based on the evidence available, it is my medical opinion that the condition is at least as likely as not (50% or greater probability) related to [specific in-service event, exposure, or condition] that occurred during [dates or period of military service]. This conclusion is supported by [brief medical reasoning: symptom onset, medical research, known risk factors, or pathophysiology], and there is no more medically probable non-service explanation for [Veteran Name]’s condition.
If your claim has a well-documented timeline, supportive treatment records, and no conflicting medical opinions, a streamlined nexus letter like this typically works very well.
Does a Nexus Letter Ever Need More Detail?
Sometimes, you’ll need your nexus letter to address extra factors to fully establish service connection. In these situations, a basic opinion isn’t enough:
You had a negative C&P exam: Your doctor should explain why the examiner’s reasoning is incorrect, incomplete, or not supported by the evidence in your file.
You have other possible causes for your condition: Your doctor should address the most common alternative explanations and show why they don’t fully explain your symptoms.
You’re filing a secondary condition: Secondary claims require a clear cause-and-effect explanation. Your nexus letter should briefly explain how your primary condition caused or aggravated the secondary one.
Your symptoms appeared years after service: If your symptoms were delayed, your doctor needs to explain the medical basis for delayed onset and why it still connects to your service.
You’re dealing with a weaker medical link:n Some conditions—like sleep apnea secondary to tinnitus—require stronger reasoning. These letters often need medical literature and more detailed medical analysis to hold weight with the VA.
Do You Need a Nexus Letter for Your Condition?
You usually only need a nexus letter when the medical connection to service isn’t already obvious. Secondary conditions almost always require one; straightforward primary conditions often do not.
When Primary Conditions Need Nexus Letter
Most primary conditions don’t need a nexus letter. These are disabilities that clearly began during service or are directly tied to an in-service injury, illness, or event.
When the service connection is obvious, such as combat related PTSD, the VA usually doesn’t require a separate medical link.
Some exceptions include:
Your symptoms developed years after discharge but are still tied to something that happened in service.
Your condition isn’t presumptive — meaning it’s not automatically granted under VA rules.
A prior C&P examiner said there’s no medical link between your condition and your service.
In these cases, a well-written nexus letter can help fill the gap and give the VA the medical reasoning it needs to approve your claim.
If you can’t get a nexus letter, buddy statements and lay statements can sometimes bridge the gap.
Why Secondary Conditions Almost Always Require One
Secondary conditions are disabilities caused or worsened by another service-connected condition
Nexus letters for secondary conditions need to clearly explain the “cause and effect” relationship. They need to show the following things:
How the first condition caused or worsened the second.
The timeline of each condition
Rule out other possible causes, since secondary conditions may have multiple contributing factors.
Secondary conditions are extremely common in sleep apnea claims and almost always require a nexus letter
How Much Do Nexus Letters Cost?
Nexus letters can range from free to over $3,000 depending on provider expertise and case complexity. A higher cost doesn’t guarantee a stronger medical opinion.
Situations Where You Can Get a Cheap or Free One
Sometimes you can get a strong nexus letter for cheap or even free — especially if your VA disability is straightforward and you handle most of the prep yourself.
You have a good relationship with your PCP: Doctors who know your medical history are more likely to write a letter or include the nexus opinion directly in your records.
You do research and front-end work: Organizing your evidence, timeline, and summary makes the doctor’s job easier and reduces the time they need to spend reviewing your case.
You have a relatively simple case: If the link between your service and condition is obvious, a basic letter from your provider may be enough. For example, nexus letters for tinnitus are usually simple because veterans are known to have have hearing problems after service.
Be prepared to spend a little bit regardless since most doctors want to be paid for their time.
When Nexus Letters are Expensive and Why
Some nexus letters cost more because the case requires extra time, expertise, or effort to verify.
You change doctors frequently: Without a consistent provider who knows your history, new doctors must spend more time reviewing records before forming an opinion.
You have a secondary condition: These claims require detailed medical reasoning to explain how one condition caused or aggravated another, which often means hiring a specialist.
Limited local resources: If there aren’t many qualified providers nearby, you may need to pay for a specialist review or use an independent medical examiner (IME) online.
If your case is especially complex, it may be worth investing in a specialist who can provide a detailed, well-supported medical opinion that meets VA standards.
What Happens After You Submit Your Nexus Letter & Next Steps
The VA reviews your nexus letter alongside your C&P exam and medical records. The strength of the medical reasoning determines how much weight the letter carries in your claim.
A VA Rater Reviews it
Once your nexus letter is submitted, a VA rater reviews it closely. From my experience, here’s what they care about most:
The doctor is actually qualified: Not every provider can give a strong opinion on every condition. For example, a nurse practitioner usually can’t give the same weight on sleep apnea as a pulmonologist.
The doctor reviewed real evidence: Raters can spot a five-minute template letter. They want to see that your doctor actually looked at your service records, medical history, and the full context of your claim.
The doctor addresses conflicting evidence: If you’ve had a negative C&P exam or previous denials, your nexus letter must explain why those opinions are incomplete or incorrect. VA examiner opinions carry a lot of weight, so your doctor needs to take them seriously.
Your Claim is Approved, Deferred, or Denied
Below are the three outcomes that could occur. Your claim could be:
Deferred: If your VA claim is deferred, VA needs more information before deciding, usually because there’s conflicting or incomplete evidence that must be clarified.
Approved: The VA accepted your nexus letter and found the medical reasoning strong enough to grant service connection.
Denied: The VA may deny a claim with a nexus letter if it was deemed insufficient or the rater did not properly weigh the opinion against other evidence.
Submit the Right Type of Appeal
Before appealing, do a thorough audit of your entire submission to make sure your evidence, nexus letter, and medical reasoning are as strong as possible.
Here are your three appeal options:
Supplemental Claim: Use this when your claim has evidence gaps. If the VA acknowledges your evidence but still explains clear issues, you’ll need stronger or new documentation to move forward.
Higher-Level Review (HLR): Choose this when you already have a strong claim and need a more thorough review. If the VA didn’t address your nexus letter or overlooked key evidence, an HLR gives a senior rater the chance to correct it.
Board of Veterans’ Appeals: Go this route when your case is solid but keeps getting denied due to complexity. In my experience, some conditions—like sleep apnea—often aren’t approved until they reach the Board because of how detailed and technical the evaluation needs to be.
Nexus Letter Myths vs Facts
Many veterans misunderstand how the VA uses nexus letters. The truth is that the VA weighs all medical opinions by their accuracy and reasoning—not by whether they come from private or VA doctors
Myth: The VA always discounts private nexus letters.
The VA weighs all medical evidence based on its probative value (how detailed, reasoned, and credible it is). A well-supported private opinion can carry just as much weight as a VA doctor’s.
Myth: Paid nexus letters are better than free nexus letters
Paying for a letter doesn’t guarantee success. If the letter is templated or lacks individualized reasoning, it can actually be given less weight by the VA.
Myth: VA doctors are always superior to private doctors.
Neither has automatic priority — what matters is the quality of the medical opinion. In fact, private doctors sometimes provide stronger reasoning, especially if VA examiners overlook evidence.
Myth: If the VA doesn’t mention your nexus letter in the decision, it doesn’t matter.
The VA is required to consider all evidence. If your nexus letter isn’t addressed, that could be a procedural error and grounds for appeal. For example, examiners often overlook strong nexus letters for sleep apnea, but you can still overcome this with clear medical reasoning and properly submitted appeal
Myth: Symptoms alone are enough for a nexus letter.
Symptoms must be tied to a diagnosis and connected to service (or to a service-connected condition). Without that link, a nexus letter won’t hold weight.
Myth: Every VA claim requires a nexus letter.
Not always. If your condition was diagnosed and documented during service, a nexus letter may not be necessary at all.
Final Thoughts on Nexus Letters
In short, a VA nexus letter is a critical tool for proving the connection between your service and your medical condition.
Knowing what it is, who can write it, and what makes it effective can dramatically improve your chances of a successful claim.
By approaching nexus letters strategically and ensuring your letter is credible, well-documented, and tailored to your condition, you give yourself the strongest possible support for your VA disability claim.
FAQ
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The cost of a nexus letter can vary — some are free, while others may range from around $500 to several thousand dollars. However, a higher price does not automatically mean a better letter. What matters most is finding a trusted doctor who provides a well-reasoned, individualized opinion. Be cautious with paid services that simply copy and paste; the VA gives little weight to generic letters.
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A veteran cannot submit a nexus letter on their own, but they can draft a template, organize supporting evidence, and then have a doctor review and finalize it. This approach is often more affordable than paying for a fully written letter from scratch.
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Technically, VA doctors can write nexus letters, but many choose not to. The reason is often a conflict of interest — their role is to provide treatment within the VA system, not to support or challenge disability claims.
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Yes, for secondary claims, a nexus letter is even more crucial because it explains how one service-connected condition caused or aggravated another.
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Be direct and professional. Bring your medical records, explain why you believe your condition is service-related, and ask if your doctor feels comfortable providing a medical opinion.
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A nexus letter is treated as medical evidence and becomes part of your VA claims file. It is not a VA form, but supporting documentation for your claim.?
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You generally don’t need a nexus letter for a higher rating if you are already service connected for that condition. You only need one for a rating increase if you are filing for a new condition.
