Nexus Letter Examples: Best Templates for Sleep Apnea, PTSD, & More

Oct 8

There's absolutely no shortage of nexus letter templates online — trust me, I've seen them all. Way too many veterans just download these fill-in-the-blank examples and hand them straight to their doctor without customizing them for their unique situation.

The result? The VA denies claims left and right that rely on these generic templates they've seen hundreds of times.

Writing a basic template is the easy part. The hard part is customizing it so your doctor knows exactly what to include and the right way to phrase it.

This guide provides a nexus letter template designed to far surpass generic examples, along with expert tips on customizing it specifically for your condition.

Why Most Nexus Letter Templates Don’t Work

You can’t use a basic template for a nexus letter because each condition needs a different level of evidence, reasoning, and medical detail.

A nexus letter isn’t a form — it’s a personalized medical opinion linking your condition to service. Generic templates fail because they treat every case the same.

Pre-Written Examples Mislead Your Doctor

Many prewritten nexus letter templates make it way too easy for a doctor to just fill in the blanks rather than provide a detailed, professional opinion.

The result? Your doctor feels like they're just signing a form, instead of actually analyzing your unique case and linking your condition to your service. Here’s an example of this below:

Bad: "This veteran's back pain is due to military service."
Good: "This veteran's chronic lower back pain began during active duty after repeated heavy lifting, with no prior history of back problems. Medical records confirm the onset and progression of symptoms during service, and alternative causes have been ruled out."

Most doctors have limited experience with nexus letters. They often aren’t familiar with the specific language the VA looks for or the evidence it requires.

A good nexus letter template gives the doctor a more detailed understanding of what evidence and reasoning is needed for your case.

Templates Often Make Your Letter Look Biased

Another problem with generic templates is that they are designed to reach a conclusion immediately. They often start with the outcome rather than building the argument from the ground up. For example:

Bad template: “It is my opinion that the veteran’s back pain is related to military service.”
(Conclusion first — no explanation or supporting evidence.)
Good approach: “The veteran’s back pain began during active duty after repeated heavy lifting. Medical records confirm the onset and progression of symptoms, and alternative causes have been ruled out. Based on this evidence, it is at least as likely as not that the condition is service-connected.”
(Evidence leads to conclusion — logical and persuasive.)

When a doctor begins with the conclusion, there’s a risk they will try to make the evidence fit the answer instead of letting it naturally lead to the conclusion.

This guide is designed to help you create a template that clearly outlines your doctor’s work. The template will reflect your understanding of the VA’s requirements and incorporate the most effective reasoning strategies for your specific condition.

Nexus Letter Basics: What Veterans Need to Know

A nexus letter must include a few key elements to be accepted by the VA:

Proper formatting: The letter should include specific headers, dates, reference information, your name, and signatures to ensure professionalism and clarity.
Veteran's identifying information: Your name, date of birth, service details, and veteran SSN should be properly included.
Doctor's qualifications and medical specialty: The letter must come from a licensed medical professional with relevant expertise, and should clearly state the doctor's medical specialty to establish credibility and authority
Clinical relationship: The letter should outline the clinical relationship between the doctor and you, detailing treatment history, frequency of contact, and ongoing medical care.
Diagnosis: The letter should clearly state the medical diagnosis, ideally including the corresponding medical code, so the VA can easily match it to the appropriate condition
Medical rationale: Thorough explanation of how the condition is linked to service, citing thorough evidence records, observations, and relevant evidence
Consideration of alternative causes: The doctor should rule out other potential causes to show an unbiased opinion. In addition, if the VA has already given their feedback, the doctor should address this as well.
VA language: The VA requires nexus letters to include at least “at least as likely as not” language to establish a service connection for a condition
Signature and date: A signed and dated letter from the medical professional.

Simple Starter Nexus Letter Template

Header – Credentials & Introduction

I am a licensed [Doctor’s Title], specializing in [Medical Specialty].
I have been evaluating [Veteran Name] since [Start Date], with appointments occurring [Frequency and Nature of Visits], regarding [Condition / Medical Issue].

Purpose of the Letter

This letter provides a medical opinion on [Condition] and its connection to [Veteran Name]’s military service.

Records Reviewed

I reviewed [Veteran Name]’s service treatment records, which show [Key Events].
I also reviewed post-service medical records and diagnostic results. Together, these records provide important context for how [Condition] developed and progressed.

Relevant Medical History & Symptom Timeline

The veteran’s symptoms began [Describe Onset] and have progressed as follows: [Describe Progression and Impact]. These symptoms match [Condition] and are consistent with the veteran’s medical history.

During this time, [Veteran Name] has tried treatments such as [List Treatments], which provided [Describe Effectiveness].

Medical Reasoning and Causation

I considered other possible causes, including [List Alternatives], but found them less likely than a service-related cause.

Supporting evidence includes [List Records / Exams / Buddy Statements / Diagnostics] and supports the connection between [Veteran Name]’s condition and military service because [Give Specific Examples].

Analysis of VA Examination (if applicable)

In reviewing the VA exam from [MM/DD/YYYY], the examiner concluded [Insert VA Examiner’s Conclusion].

After reviewing the veteran’s full medical and symptom history, I find this conclusion [Explain Why Insufficient or Inaccurate].

Formal Nexus Opinion

It is my professional medical opinion that [Condition] is at least as likely as not (50% or greater probability) related to [Veteran Name]’s military service.

Signature Block

Sincerely,
[Doctor’s Name, Title, Credentials]
[Date]

Nexus Letters for PTSD

The best approach to a PTSD nexus letter depends on whether the claim is direct or secondary.

For direct claims, the letter should clearly explain why PTSD to a specific in-service event, such as combat, MST, or other traumatic events.

For secondary claims, the letter should show how PTSD was caused or worsened by another service-connected condition, like chronic pain, TBI, or a related mental health issue.

Direct Connection to PTSD

It is well known that the VA automatically recognizes direct connections for events like combat or witnessing a death, but other cases aren’t always as clear.

If your PTSD symptoms appear later, or if your claim is based on a non-combat event, you may still need a nexus letter to establish the connection to service.

DSM-5 Diagnosis: Your letter must include a DSM-5 PTSD diagnosis from a certified specialist (Psychiatrist or Psychologist) Regular doctors cannot provide this diagnosis for VA claims.
Military Cause: Some of the most common are sexual assault/MST, training accidents, witnessing death or injury outside combat, serious vehicle accidents, or natural disasters while in service).
Medical Rationale: For direct PTSD cases, the most important part of the nexus letter is building a clear timeline that shows when symptoms began after the in-service stressor and why other causes don’t explain it.
Relevant Evidence: The biggest challenge in direct PTSD claims is proving your incident happened. Buddy or lay statements are extremely helpful here since many of these incidents are not documented. Doctor/therapy notes are also helpful for establishing the cause

Secondary Connection to PTSD

For secondary claims, the stressor is already established — the issue now is proving the link between an existing service-connected disability and PTSD

DSM-5 Diagnosis: Your letter must include a DSM-5 PTSD diagnosis from a certified specialist (Psychiatrist or Psychologist) Regular doctors cannot provide this diagnosis for VA claims.
Primary Condition Connection: The letter must clearly identify which service-connected condition caused or worsened the PTSD. Common examples include chronic pain, disfigurement, or traumatic medical experiences tied to another disability.
Medical Link: The provider should explain the biological or psychological pathway connecting the conditions (for example, how chronic pain or physical limitations led to anxiety, social withdrawal, and ultimately PTSD).
Rule out other possible causes: should be a major focus since secondary PTSD claims often have many competing explanations.
Relevant Evidence: Unique medical literature linking PTSD to the specific secondary condition is often the strongest form of support. Additionally, therapy records, medical notes, and credible lay or spouse statements can help demonstrate the secondary connection.

Nexus Letters for Sleep Apnea

Sleep apnea is one of the tougher conditions to prove for the VA, so your nexus letter should be detailed and clear. Most sleep apnea cases are filed as secondary claims, as sleep apnea is rarely a direct cause of a service conditon

Here's a simple way to customize the basic template for sleep apnea:

Qualified Medical Professional: You need a diagnosis from a sleep specialist or pulmonologist who has experience treating sleep apnea. A primary care doctor’s opinion usually carries little weight because they generally lack the expertise to interpret sleep studies or manage long-term treatment.
Primary Condition Connection: The most likely conditions you can connect to sleep apnea are the ones that have the most medical literature connecting the two together. some of these include PTSD, Rhinitis, and Sinusitis.
Disability Benefits Questionnaire (DBQ): The provider should include or reference a DBQ, which details your symptoms, functional limitations, and treatments such as CPAP.
Relevant Evidence: The doctor should include and reference as much relevant evidence as possible, such as sleep study results, medical literature, buddy/lay statements, etc.
Medical Rationale: This is the trickiest part of sleep apnea nexus letters. The doctor must evaluate all. This includes citing sleep study results, clinical evaluations, and any supporting medical literature to back up each statement. The provider should clearly lay out the logic connecting the evidence to the diagnosis and rule out other possible causes as well.

This helps show the VA why the condition is ongoing, clinically significant, and requires medical management.

Nexus Letters for Tinnitus

Not every veteran actually needs a nexus letter for tinnitus. In many cases, if you're already service-connected for hearing loss, the VA assumes tinnitus came from the same source, so no separate nexus is required.

A nexus letter is usually only necessary if your tinnitus is being claimed on its own without documented hearing loss, or if it stems from another condition like TBI or hypertension.

Primary Tinnitus Claims

A nexus letter for primary tinnitus must clearly show that your tinnitus is directly related to military service, even if it wasn’t diagnosed immediately.

Medical Diagnosis: Diagnosis from an Audiologist or ENT confirming tinnitus, ideally documenting severity and ruling out non-service causes.
Evidence: Lay statements describing onset and progression, plus service records showing in-service noise exposure or other events likely to cause tinnitus.
Medical Rationale: Clear explanation linking the tinnitus to military service, addressing the timeline, ruling out other causes, and referencing relevant studies or medical literature.

Secondary Tinnitus Claims

Topic sentence: A nexus letter for secondary tinnitus must explain the medical connection between the tinnitus and an already service-connected condition.

Medical Diagnosis from a Specialist: The specialist must document tinnitus and explain how it is caused or aggravated by the primary condition (e.g., TBI, hypertension, neck injury). ENT is usually best for secondary conditions.
Evidence: You need extensive evidence demonstrating that Tinnitus is medically related to the secondary condition you are targeting. Lay statements and medical records are helpful for describing symptom onset so you can connect the two conditions
Medical reasoning: Demonstrates how the primary service-connected condition caused or worsened tinnitus. Your doctor must throughly describe the timeline for each condition so they can connect the two
Supporting literature: References to medical studies or research showing a link between the primary condition and tinnitus strengthen the nexus opinion.

Nexus Letters Can’t Be Based on Symptoms Alone

A key mistake many veterans make is trying to get a nexus letter for a symptom rather than an actual medical condition.

The VA doesn't grant service connection for vague complaints like "back pain" or "migraines" alone — they need a diagnosed disability that explains those symptoms and supports your disability claim.

Back Pain

Pain itself isn’t considered a disability in the VA’s eyes. You need a specific medical diagnosis such as degenerative disc disease, herniated disc, spinal stenosis, or lumbar strain — something that explains the cause of your pain.

Once you have that, your nexus letter can connect that condition to your service — for example, repeated heavy lifting, airborne training, or a documented back injury on duty.

If your medical records don’t include imaging (like an X-ray or MRI) or a clear diagnosis, the VA can deny your claim even if your pain started in service. Ask your doctor to identify the exact condition before writing the nexus letter.

One common mistakes is submitting a letter that says only “chronic back pain.” The VA doesn’t rate pain alone — it must be tied to a diagnosed, functional impairment.

Migraines

Simply stating that you get frequent headaches isn’t enough for the VA to grant a claim. A doctor must diagnose you with a condition such as migraine disorder, tension-type headaches, or cluster headaches so that your nexus letter has something concrete to connect to your service.

If you’re claiming migraines, make sure your doctor explains how they began — for example, after a head injury, from stress or PTSD, or due to medication side effects.

The VA rates migraines under Diagnostic Code 8100 based on how often they’re “prostrating,” meaning they completely disable you. Keeping a migraine journal and having your doctor reference it in the nexus letter can make a big difference.

When filing your claim, make sure your doctor doesn’t call them “frequent headaches” and instead uses the diagnosed condition name. The VA treats that as a vague symptom, not a compensable disorder.

Flat Feet

Saying you have sore feet or fallen arches isn’t enough for the VA to approve your claim.

But if you’re diagnosed with pes planus (flatfoot), plantar fasciitis, or posterior tibial tendon dysfunction, your nexus letter can connect those conditions to military activities like long marches, running in boots, or carrying heavy packs.

If your entrance exam showed flat feet, the focus should be on how service aggravated the condition — not just that it existed. The nexus letter must clearly describe how your time in service made your symptoms worse.

Notes about orthotics, restricted duties, or documented foot pain in service records all strengthen your claim. These details help show that your flat feet were aggravated by service.

Sleep Apnea Nexus Letter Example (Secondary Condition to PTSD)

Thompson Sleep Center
Dr. Sarah Thompson, MD – Board-Certified Sleep Specialist
123 Health Way, City, State ZIP
Phone: (555) 123-4567 | NPI: 1234567890

Date: October 4, 2025

Re: John M. Reynolds, DOB 03/14/1985
Service: U.S. Army, 2003–2010

To Whom It May Concern,

I have evaluated Mr. John M. Reynolds for sleep-related concerns. Based on his clinical history, sleep study results, review of service records, and ongoing medical treatment, it is my professional opinion that his obstructive sleep apnea (OSA) is at least as likely as not caused or aggravated by his service-connected post-traumatic stress disorder (PTSD). Mr. Reynolds’ sleep apnea is characterized by chronic sleep disruption, excessive daytime fatigue, morning headaches, and restless sleep, which began after his military service and have persisted despite conservative treatments.

Mr. Reynolds was diagnosed with moderate obstructive sleep apnea via polysomnography on July 22, 2024, with an apnea-hypopnea index (AHI) of 23. His symptoms are consistent with the effects of PTSD, including disrupted sleep patterns and nighttime arousals, which are well-documented in the medical literature as contributing factors to the development and exacerbation of sleep apnea. Additionally, long-term use of medications for PTSD and anxiety has contributed to weight gain, further increasing the likelihood of airway obstruction, and in-service nasal trauma has further impacted his breathing during sleep.

After reviewing all relevant VA and private medical records, as well as statements from family members noting loud snoring, gasping, and pauses in breathing, it is my conclusion that alternative causes such as aging, alcohol use, or general obesity alone do not fully account for the onset or severity of his sleep apnea. Mr. Reynolds requires ongoing CPAP therapy, and prior lifestyle interventions have been insufficient in managing his condition.

Based on this thorough evaluation, it is my medical opinion that Mr. Reynolds’ obstructive sleep apnea is at least as likely as not secondary to his service-connected PTSD. This nexus supports his VA claim by establishing a clear connection between his current disability and his military service.

Sincerely,

Dr. Sarah Thompson, MD
Board-Certified Sleep Specialist
[Signature]

Final Thoughts on Nexus Letters

This guide provides clear, real-world examples of nexus letters to help veterans understand how to effectively establish service connection for their medical conditions.

Each example highlights the critical components that VA reviewers look for, including detailed medical reasoning, references to service records, and precise language linking a condition to military service.

By reviewing these examples, veterans and their healthcare providers can see how a properly drafted nexus letter strengthens a claim, avoids common pitfalls, and increases the likelihood of a successful VA decision.

FAQ

A nexus letter can vary in format, but it generally includes the veteran’s diagnosis, relevant medical and service history, and the doctor’s opinion connecting the condition to military service. While the layout differs, the key is that it clearly explains how the condition is “at least as likely as not” related to service.
While a veteran cannot write their own nexus letter, they can create a detailed template or outline to guide their doctor. This template can include the veteran’s medical history, relevant service events, and the specific connection they need the doctor to address. By providing this information, the doctor has a clear roadmap for writing the letter, ensuring it meets the VA’s requirements and strengthens the claim
A general rule is that a nexus letter is needed when the VA does not have enough evidence to establish a service connection or when there’s a legitimate question about whether the condition is related to service. Essentially, it’s used to fill gaps in the record and provide the medical opinion necessary to support the claim

Jack Gilbert