Original research

The Missing Nexus: The Top Reason VA Claims Are Denied

An analysis of 604,548 service-connection denials from the Board of Veterans' Appeals. In 93.6% of them the record showed which of the three basic elements the Board found missing, and one stands out far above the rest: the medical nexus.

60.5%missing a medical nexus
21%no current diagnosis
18.5%no in-service event

How this research is built: every Board of Veterans' Appeals decision published by VA is public, and anyone can read one at a time. RateMyVSO downloads and analyzes the complete published record, classifying which element, current diagnosis, in-service event, or medical nexus, the Board found missing in each denial, using a mix of automated text analysis and targeted AI review for the harder cases. The result is one of the largest structured research datasets built from the published Board record. It updates automatically every week as new decisions publish.

Updated August 2026

The single most common reason claims are denied

To be service connected, a claim generally needs three things: a current diagnosed condition, an in-service event or exposure, and a medical nexus, the doctor's opinion connecting the two. When the Board denies on service connection, we can read which element it found missing. Across 565,882 classified denials, here is how often each element was the one that fell short:

Missing medical nexus60.5%
342,351 denials, the medical opinion linking the condition to service
No current diagnosis21%
118,941 denials, no present, diagnosed disability on record
No in-service event18.5%
104,590 denials, nothing in service tied to the condition
What a nexus is, in plain terms: a medical opinion that the condition is "at least as likely as not" related to service. It is the bridge between the diagnosis and the service, and it is the piece missing from roughly six of every ten denials.

What the presence of a nexus opinion looks like at the Board

The same corpus shows the flip side. Grouping decisions by who wrote the medical opinion in the file, the grant rate rises sharply when a private opinion is present:

Both a private and a VA opinion69.5%
76,921 decisions
A private doctor opinion65.5%
53,751 decisions
VA examiner opinion only38.2%
352,096 decisions
No medical opinion in the file38.4%
532,431 decisions
Across the published record, appeals with a private medical opinion in the file were granted at roughly three times the rate of those with no medical opinion at all. This describes the pattern in decided cases; it is not a prediction about any individual claim.

Denial reasons by condition

The fifteen conditions with the most service-connection denials, and how often each denial turned on a missing nexus versus a missing diagnosis or in-service event:

ConditionSC denialsMissing nexusNo diagnosisNo in-service
Hearing loss DC 6100 54,951 59.2% 29.5% 11.3%
Degenerative arthritis, other than post-traumatic DC 5003 35,142 65.9% 13.5% 20.6%
Posttraumatic stress disorder DC 9411 34,620 37.3% 37.2% 25.5%
Tinnitus, recurrent DC 6260 23,330 70.7% 12.1% 17.2%
Hypertensive vascular disease DC 7101 22,808 67.2% 8.4% 24.5%
Lumbosacral or cervical strain DC 5237 22,802 63.6% 19% 17.4%
Intervertebral disc syndrome DC 5243 21,574 79.4% 4.1% 16.5%
Sleep Apnea Syndromes DC 6847 17,156 65.6% 15.9% 18.5%
Paralysis of sciatic nerve DC 8520 15,481 55.1% 23.6% 21.3%
Diabetes mellitus DC 7913 14,841 56.5% 10.1% 33.4%
Major depressive disorder DC 9434 13,298 66.6% 20.6% 12.8%
Knee, other impairment of DC 5257 11,342 64.8% 20.4% 14.8%
Ankle, limited motion of DC 5271 10,484 53.6% 30.1% 16.2%
Migraine DC 8100 10,393 62.5% 19.1% 18.5%
Arteriosclerotic heart disease DC 7005 9,867 61.4% 20.1% 18.5%

Methodology

This report aggregates published decisions of the Board of Veterans' Appeals. Each service-connection denial is classified by which of the three elements of service connection (current diagnosis, in-service event, medical nexus) the Board identified as missing, using the language of the decision. Increased-rating, effective-date, and other non-service-connection denials are outside this three-element test and are not counted here. Of 604,548 service-connection denials, 565,882 (93.6%) carried enough language to classify. The grant-rate figures group decisions by the source of the medical opinion in the file. Data as of August 2026; the underlying figures refresh weekly.

Cite this research

RateMyVSO. (August 2026). The Missing Nexus: An Analysis of 604,548 Board of Veterans' Appeals Denials. https://ratemyvso.net/dc/denial-reasons-report

Free to cite and link with attribution. Figures derived from published Board of Veterans' Appeals decisions.

Educational and encyclopedic only, not legal advice, and not a prediction of any individual claim. Figures describe patterns in published Board decisions. For help with a claim, find a VA-accredited representative.