TBI Secondary Conditions Under 38 CFR 3.310(d): What the Rule Actually Says

If you have a service-connected traumatic brain injury, five conditions can be connected to it under 38 CFR § 3.310(d) without a nexus opinion: parkinsonism, unprovoked seizures, certain dementias, depression, and hormone deficiency diseases from hypothalamo-pituitary changes. Each carries its own severity requirement and time window. This rule is not new, it is not a presumptive list in the way most articles describe it, and the parts nobody explains are the parts that decide claims.

The five conditions, exactly as written

Under § 3.310(d)(1), in a veteran with a service-connected TBI, the following are held to be the proximate result of that TBI, in the absence of clear evidence to the contrary:

Two details in that table get missed constantly. Parkinsonism and unprovoked seizures carry no time limit at all, so a seizure disorder appearing thirty years after a moderate TBI still falls inside the rule. And depression is the only one of the five that reaches mild TBI.

Why calling these "presumptives" is wrong, and why it matters

VA said so itself, in writing, in 2013.

Responding to public comments on the proposed rule, VA noted that many commenters had misunderstood what it was doing, and stated plainly that it was not establishing presumptions of service connection for these conditions. VA explained the difference this way. A presumption supplies the nexus between an in-service event that is not itself disabling and a later disability. Secondary service connection instead links a new condition to a disability that is already established as service connected.

That is not a technicality. It determines where your claim starts.

A presumptive pathway like the Agent Orange list at 38 CFR § 3.309(e) can carry you from exposure to compensation. Section 3.310(d) cannot. It does nothing at all until your TBI is already service connected. VA made this explicit: the rule does not alter the requirement to first prove that a TBI is service connected before VA considers what may be secondary to it.

If you have symptoms you believe came from a head injury in service, but the TBI itself has never been service connected, this rule is not your pathway yet. Your first claim is the TBI.

How VA decides whether your TBI was mild, moderate, or severe

This is where most claims are quietly won or lost, and it is the least-explained part of the regulation.

Section 3.310(d)(3) sets out a table with five factors. It is the stratification VA and the Department of Defense both adopted for evaluating TBI severity.

Three rules govern how that table is applied, and each one can move a claim.

Severity is judged at the time of injury, not today. Paragraph (d)(3)(ii) states that the determination rests on TBI symptoms at the time of injury or shortly thereafter, rather than the current level of functioning. A veteran who is doing reasonably well now can still have had a moderate TBI in 2006. The evidence lives in your service treatment records, the line-of-duty documentation, the medevac notes, and sometimes in what the people around you remember.

You do not need to meet every criterion. VA will not require that a TBI satisfy all the criteria at a severity level to be classified there. One qualifying factor is enough.

Ties go up, with one exception. If a TBI meets criteria in more than one category, VA ranks it at the highest level in which any criterion is met, except where the qualifying criterion is the same at both levels. In practice this means normal or abnormal imaging cannot push you to severe, because it appears identically at moderate and severe. Neither can alteration of consciousness beyond 24 hours. VA added that exception deliberately, noting that a literal reading would otherwise classify every TBI as severe.

Here is what this adds up to. A veteran with normal imaging, a GCS of 14, and 45 minutes of documented loss of consciousness has a moderate TBI under this table, because LOC over 30 minutes lands in the moderate column and one criterion is enough. That single line in an old record is the difference between qualifying for all five conditions and qualifying for just one, since depression is the only condition that reaches mild TBI, and on a twelve-month window rather than three years.

What happens if you fall outside the rule

You are not out of options. You are in a different lane.

Paragraph (d)(2) is unambiguous: neither the severity levels nor the time limits preclude a finding of service connection for conditions shown by evidence to be proximately due to service-connected TBI. If your claim does not fit the windows or the severity, VA will develop and decide it under generally applicable principles of service connection.

"Generally applicable principles" means the ordinary secondary service connection framework of 38 CFR § 3.310(a), and it means the burden of showing the link comes back to the evidence. VA acknowledged this directly in 2013, explaining that in most cases the nexus element is proven through a medical opinion from an appropriate professional, with citation to medical authorities where needed. VA also pointed to Sacks v. West, 11 Vet. App. 314, 317 (1998), for the principle that medical literature alone is usually not enough to establish that a particular veteran's condition was caused by service.

So the practical map looks like this. Inside the rule, you need documentation of severity and timing. Outside it, you need a reasoned medical opinion. Conditions the rule never mentions, such as post-traumatic headaches, sleep disorders, or anxiety, also sit in the second lane. VA considered adding several of them in 2013 and declined, concluding that the evidence supported case-by-case determination instead.

That second lane is larger than the first. Most TBI veterans live in it.

The parkinsonism trap

One distinction deserves its own section, because it cuts both ways depending on your service.

All Parkinson's disease is parkinsonism. Not all parkinsonism is Parkinson's disease. VA addressed this in 2013 and drew the line carefully. Section 3.310(d) uses the broader term parkinsonism, including Parkinson's disease, because the underlying research covered the wider category. The Agent Orange presumptive list at § 3.309(e), by contrast, is limited to Parkinson's disease alone, because the report behind that rule examined only that diagnosis.

A Vietnam-era veteran with drug-induced parkinsonism or multiple system atrophy does not fit the herbicide presumptive, even though the chart says parkinsonism. A veteran with a service-connected moderate TBI and that same diagnosis does fit § 3.310(d). One word, two pathways. The wrong one gets chosen more often than it should.

What the medical evidence behind the rule actually shows

The rule rests on the Institute of Medicine report Gulf War and Health, Volume 7: Long-Term Consequences of Traumatic Brain Injury. VA selected only conditions the IOM placed in its top two evidence categories, sufficient evidence of a causal relationship or sufficient evidence of an association, and declined to extend the rule to the weaker limited or suggestive category.

Some of the underlying findings are worth knowing if you are building a claim outside the windows. One frequently cited study found that in the first year after moderate to severe TBI, 49 percent of patients showed evidence of psychiatric illness, compared with 34 percent after mild TBI and 18 percent in a comparison group, with risk concentrated in the 6 to 12 month window (Fann JR et al., Archives of General Psychiatry, 2004;61(1):53-61). Research on head injury and Parkinson's disease risk in twins found an association with TBI involving loss of consciousness or post-traumatic amnesia (Goldman SM et al., Annals of Neurology, 2006;60(1):65-72). Work on repeated mild injury has described a period after brain injury during which the brain remains particularly vulnerable to further damage (Prins ML et al., Journal of Neurotrauma, 2013;30(1):30-8).

A well-built opinion for a claim outside § 3.310(d) does not simply attach studies like these. It explains why the mechanism applies to your injury, your timeline, and your record.

Where this leaves you

The rule is narrower than the internet suggests and more useful than most veterans realize. It is narrower because it is not a presumptive list and it does nothing without a service-connected TBI already in place. It is more useful because the severity table is generous in a way almost nobody explains: one qualifying criterion, measured at the time of injury, is enough.

Here is what the evidence needs to show, and why. First, that your TBI is service connected. Second, where it falls on the severity table, proven from records made at or near the time of injury. Third, when the secondary condition appeared. Get those three on paper and, for these five conditions, the regulation does the rest of the work. Miss any of them and you are back to needing a medical opinion, which is a fair fight but a different one.

Sources and further reading

• 38 CFR § 3.310(d), including the severity table at (d)(3) and the savings clause at (d)(2). Section source credit: 44 FR 50340, Aug. 28, 1979, as amended at 66 FR 18198; 71 FR 52747; 78 FR 76208, Dec. 17, 2013.

• Federal Register, "Secondary Service Connection for Diagnosable Illnesses Associated With Traumatic Brain Injury," final rule, 78 FR 76196 (Dec. 17, 2013), RIN 2900-AN89, effective January 16, 2014.

• Federal Register, "Clarification of VA's Processing of Survivors Benefits Claims," final rule, 91 FR 2709 (Jan. 22, 2026), RIN 2900-AR32, effective February 23, 2026. The source of the 91 FR 2713 nomenclature citation.

• Institute of Medicine, Gulf War and Health, Volume 7: Long-Term Consequences of Traumatic Brain Injury.

• 38 CFR §§ 3.309(e), 3.114; 38 U.S.C. § 5110(g); 38 CFR § 4.124a, Diagnostic Code 8045.

• Sacks v. West, 11 Vet. App. 314, 317 (1998).

• Fann JR, et al. "Psychiatric illness following traumatic brain injury in an adult health maintenance organization population." Archives of General Psychiatry. 2004;61(1):53-61.

• Goldman SM, et al. "Head injury and Parkinson's disease risk in twins." Annals of Neurology. 2006;60(1):65-72.

• Prins ML, et al. "Repeated mild traumatic brain injury: mechanisms of cerebral vulnerability." Journal of Neurotrauma. 2013;30(1):30-38.

This article is educational and is not legal advice. Military Disability Nexus provides clinical medical opinions and documentation, not claims representation.