A nexus letter is a medical opinion that connects your current disability to your military service. For many claims—especially those without clear service treatment records—a strong nexus letter is the difference between approval and denial.
What Is a Nexus Letter?
A nexus letter (also called an Independent Medical Opinion or IMO) is a written statement from a qualified medical professional that establishes a "link" (nexus) between:
- Your current diagnosed condition, AND
- An event, injury, illness, or exposure during military service
When Do You Need a Nexus Letter?
You likely need a nexus letter when:
- Your condition wasn't treated or documented during service
- There's a gap between service and when symptoms appeared
- You're claiming a condition secondary to another SC disability
- Your C&P examiner gave a negative opinion
- Your claim was previously denied and you're filing again
- The connection between service and condition isn't obvious
What Makes a Strong Nexus Letter?
Required Elements:
- Doctor's credentials: Name, specialty, license number, qualifications
- Current diagnosis: The specific condition being claimed
- Review of evidence: What records the doctor reviewed (service records, VA records, private records)
- Medical opinion: Statement using VA's required language (see below)
- Rationale: Detailed explanation of WHY the doctor reached this conclusion
- Signature and date
The Critical Language: "At Least As Likely As Not"
VA uses a "benefit of the doubt" standard. The nexus letter must state that the connection is "at least as likely as not" (50% or greater probability). This exact phrase matters.
Evidence That Wins
- ✓"It is at least as likely as not (50% or greater probability) that [condition] is due to [service event]."
- ✓"The veteran's [condition] is more likely than not caused by his military service."
- ✓"In my medical opinion, there is a greater than 50% probability that..."
- ✓Detailed rationale citing medical literature, timeline, and specific evidence reviewed
Evidence That Loses
- ✗"It is possible that..." (too speculative)
- ✗"May be related to..." (doesn't meet 50% threshold)
- ✗"Could be caused by..." (speculative language)
- ✗No rationale explaining the doctor's reasoning
- ✗Generic letter that doesn't address specific evidence
- ✗Written by unqualified provider (more on this below)
Who Can Write a Nexus Letter?
The letter must come from a competent medical professional. VA gives different weight to different providers:
| Rating | VA Criteria |
|---|---|
| Most Weight | Specialists in the relevant field (e.g., psychiatrist for PTSD, orthopedist for back) |
| Strong Weight | MD or DO (Medical Doctor / Doctor of Osteopathy) |
| Moderate Weight | PA (Physician Assistant) or NP (Nurse Practitioner) |
| Some Weight | Psychologists (for mental health only) |
| Limited Weight | Chiropractors, physical therapists (for conditions in their scope) |
How to Get a Nexus Letter
Option 1: Your Treating Physician
Ask your current doctor if they'll write a nexus letter. Pros: They know your history. Cons: Many doctors are unfamiliar with VA requirements and may refuse.
Option 2: VA Doctor
You can ask VA doctors, but many are reluctant or prohibited from writing nexus letters for claims purposes. Your C&P examiner is supposed to provide an opinion, but they may not always be favorable.
Option 3: Private Nexus Letter Services
Several companies specialize in connecting veterans with doctors who write nexus letters:
- Typically cost $500-$2,500+ depending on condition complexity
- Include records review and detailed medical opinion
- Often do phone/video consultations to understand your case
- Some offer DBQ completion as well
What to Provide Your Nexus Letter Doctor
- Service Treatment Records (STRs)
- DD-214 showing MOS, locations, dates of service
- VA medical records (request from VA or pull from My HealtheVet)
- Private medical records related to the condition
- Personal statement describing how condition started and progressed
- Buddy statements from people who witnessed your condition
- Any previous C&P exams or rating decisions
Secondary Condition Nexus Letters
For secondary claims, the nexus letter must show that your already service-connected condition caused or aggravates your secondary condition:
"It is my medical opinion that [Veteran's] sleep apnea is at least as likely as not caused by his service-connected PTSD. Medical literature demonstrates that PTSD causes chronic hyperarousal and disrupted sleep patterns, both of which are established risk factors for obstructive sleep apnea..."
Cost Considerations
| Rating | VA Criteria |
|---|---|
| Free | Treating physician (if willing), VA C&P exam opinion |
| $100-$300 | Simple nexus letter from PA/NP |
| $500-$1,000 | Standard nexus letter from MD/DO |
| $1,000-$2,500+ | Complex cases, specialist opinions, multiple conditions |
Filing Tips
- Submit nexus letter with your initial claim or as supplemental evidence
- Include all supporting records the doctor reviewed
- If appealing a denial, get a nexus that specifically addresses why the C&P opinion was wrong
- Keep a copy of everything you submit
- Consider getting nexus letters for multiple conditions at once to save on costs