Independent medical opinion (IMO) for a VA claim: what it is
Updated September 28, 2026
An independent medical opinion (IMO) is a written opinion from a clinician outside VA that answers a medical question in your claim, most often whether a current condition is at least as likely as not connected to your service. Veterans usually get one when a VA examiner's opinion was negative or never addressed the right question. When it is a service-connection opinion, it is the same thing people call a nexus letter.
IMO, nexus letter, and VA's own opinions
In everyday claims talk, an IMO and a nexus letter are the same document: a private medical opinion on the link between your condition and your service, or between one condition and another.
VA has its own, narrower use of the term. Under 38 CFR 3.328, when a claim is medically complex or controversial, VA may obtain an advisory opinion from outside medical experts at recognized medical schools or institutions. You cannot order that one; VA decides when it is warranted. A private IMO is the opinion you bring yourself.
Who can write one
VA treats medical evidence as competent when it comes from someone "qualified through education, training, or experience to offer medical diagnoses, statements, or opinions" (38 CFR 3.159(a)(1)). That includes your own treating doctor, and it includes licensed clinicians who review your records for an opinion.
What a useful IMO contains
A rater weighs the reasoning, not the letterhead. A strong opinion:
- Says which records the clinician reviewed, including service treatment records.
- States the current diagnosis and the in-service event, injury, exposure or illness.
- Gives a clear conclusion in VA's terms, such as "at least as likely as not" (a 50% or greater probability).
- Explains why, in plain clinical reasoning tied to your own history and to the medical literature.
- Deals with anything in the file that points the other way, such as a negative VA exam.
When an IMO helps most
An IMO is worth the most when the question is medical and the file has no favorable opinion on it: a denial that says there is no link, a VA exam that did not review your records, or a secondary condition (38 CFR 3.310) that no examiner addressed.
It helps least when something else is missing. Without a current diagnosis or any record of the in-service event, no opinion can fill the gap, which is why Commander Health screens your records before anyone is paid.
How Commander Health does it
Records only: you upload your records, the free screen checks for the diagnosis, the in-service event, continuity and support for the link, and a licensed clinician reviews the case. Any follow-up question comes by email; there is no appointment. The nexus letter is a flat $500. Commander Health reviews physical conditions only.
Frequently asked questions
- Is an independent medical opinion the same as a nexus letter?
- For a service-connection question, yes. Both are a private clinician's written opinion on whether your condition is connected to service.
- Can I ask VA for an independent medical opinion?
- VA decides when to obtain an outside expert opinion under 38 CFR 3.328, for medically complex or controversial claims. A private IMO is the one you obtain yourself and submit as evidence.
- Does an IMO require an exam?
- Not always. Many service-connection opinions are written from a review of the records. Commander Health works from records only.
- Will an IMO win my claim?
- No opinion can promise that. VA weighs every piece of evidence and decides the claim. A clinician signs only when the records support the opinion.