What a nexus letter is
A nexus letter is a written medical opinion from a qualified healthcare provider that connects your current diagnosed condition to your military service. It is a central piece of evidence for non-presumptive claims.
When you need one
- Filing more than 1 year after separation (outside presumptive window)
- Claiming a condition not covered by presumptive rules
- Claiming a secondary condition caused by a service-connected disability
- Your in-service records are incomplete or missing
- The C&P examiner provided an unfavorable opinion and you're appealing
What makes a strong nexus letter
The letter must contain five required elements:
1. Provider credentials
The doctor must be qualified to opine on your condition. A psychologist for PTSD, an orthopedist for joint conditions, etc. Include their license number, specialty, and CV.
2. Records review statement
"I have reviewed the veteran's complete service treatment records, VA medical records, private medical records, and lay statements." The provider must list what they reviewed.
3. Current diagnosis
A clear statement of your current diagnosed condition using accepted medical terminology.
4. The opinion statement
The opinion must state: "It is at least as likely as not (50% or greater probability) that [condition] is related to / caused by / aggravated by [military service / service-connected condition]."
This is the legal standard. "Possibly related" or "could be connected" is not strong enough.
5. Medical rationale
This is where most nexus letters fail. The provider must explain WHY, the medical reasoning that supports the connection. Strong rationale includes:
- Citing peer-reviewed medical literature
- Explaining the medical mechanism (e.g., "repeated heavy lifting causes degenerative disc changes")
- Addressing the timeline from service to current symptoms
- Ruling out other potential causes
- Referencing your specific service duties and exposures
For secondary conditions
The nexus letter must explain how your primary service-connected condition caused or chronically worsened the secondary condition. Example:
"The veteran's service-connected lumbar strain has resulted in an altered gait pattern, which has caused compensatory stress on the bilateral knees, leading to the currently diagnosed bilateral patellofemoral syndrome. This mechanism is well-documented in orthopedic literature."
Where to get a nexus letter
- Private physicians who are willing to review records and write opinions
- Independent Medical Opinion (IMO) providers who specialize in VA nexus letters
- VA physicians can sometimes provide favorable opinions, but they may be reluctant
- Some veteran service organizations can help connect you with providers
Cost
Private providers set their own fees, and VA does not pay for a nexus letter. Ask what the fee is and what the letter will cover before you hire anyone.
Red flags that weaken a nexus letter
- No records review, only what the veteran reported
- No medical rationale, only a conclusory statement
- Written by an unqualified provider (e.g., chiropractor opining on PTSD)
- Template language with no personalization to your case
- "Possible" or "may be" instead of "at least as likely as not"