TBI VA Rating

Traumatic brain injury sits in an awkward place in the rating schedule. The diagnostic code that covers it (DC 8045 under 38 CFR § 4.124a) was rewritten in 2008 to handle a problem the old framework couldn't solve. A single brain injury can produce cognitive deficits, mood changes, headaches, balance issues, sleep disruption, and personality changes, sometimes all in the same veteran. The 2008 framework tried to capture all of that with one rating mechanism. It works better than what came before. It still creates a structural problem the Board has to solve, claim by claim.

The problem is overlap. A veteran with a TBI and PTSD has symptoms that show up in both diagnostic codes. A veteran with a TBI and migraines has neurological symptoms that fit DC 8045 and DC 8100. The non-pyramiding rule says you can't rate the same impairment twice. So the Board has to decide which diagnostic code captures which symptoms, and because the TBI tiers sit 30 points apart, that decision can move a rating by 30 percentage points or more. I pulled the regulatory framework under 38 CFR § 4.124a, the DC 8045 facet structure, and Claim Raven's read of Board decisions to lay out where these claims actually land. Across 8,367 decided Board rulings on TBI from 2021 to 2026, 17.7% were granted, 33.5% denied and 48.9% remanded. A ruling is one issue the Board decided in one decision; one decision often rules on several issues. The grant rate is 7 points below the Board-wide 24.7%. TBI is one of the harder claims at the Board, and the reasons why are worth understanding before you file.

This page covers the TBI rating chart under DC 8045, what each tier pays, TBI with migraines or PTSD, the conditions 38 CFR § 3.310(d) ties to a service-connected TBI, how to prove the injury happened, the TBI C&P exam, and why VA denies TBI claims.

TL;DR

• Across 8,367 decided Board rulings on TBI from 2021 to 2026, 17.7% were granted, 33.5% denied and 48.9% remanded. The grant rate is 7 points below the Board-wide 24.7%, and remand is the most common outcome.
• DC 8045 covers three areas of dysfunction: cognitive, emotional/behavioral, and physical. Cognitive impairment and subjective symptoms are scored on a table of 10 facets, and the highest facet sets that rating at 0/10/40/70/100. A diagnosed mental disorder and physical residuals are rated under their own codes and combined.
• The pyramiding rule at 38 CFR § 4.14 and Note (1) to DC 8045 bar rating the same symptoms twice when TBI overlaps with PTSD (DC 9411) or migraine (DC 8100). Symptoms that can be clearly separated get separate ratings; symptoms that can't get one rating under whichever criteria better capture them.
• The DC 8045 table has no 30, 50 or 60 percent step, and the leap from 70 to 100 requires a facet at the "total" level.
• Under 38 CFR § 3.310(d), Parkinsonism, unprovoked seizures, certain dementias, depression and some hormone deficiency diseases are held to be secondary to a service-connected TBI when they meet the rule's severity and time limits.
• When the Board denied TBI service connection, the most common reason was that the record showed no current diagnosed disability, followed by no proof of the in-service injury. A missing link to service came up far less often.
• Combat veterans can prove the in-service injury with their own consistent account under 38 USC § 1154(b). That covers the event, not the diagnosis or the medical link.

TBI VA rating chart under DC 8045 (38 CFR § 4.124a)

Once a TBI is service connected, VA rates its residuals under Diagnostic Code 8045 in 38 CFR § 4.124a. The current version dates from October 2008; Note (5) to the code lets a veteran rated under the older version ask for a review under the current one.

The three areas VA rates

DC 8045 names three main areas of dysfunction that may result from TBI, and each is rated a different way.

• Cognitive impairment, meaning decreased memory, concentration, attention, and executive functions, is rated on the DC 8045 table ("Evaluation of Cognitive Impairment and Other Residuals of TBI Not Otherwise Classified"). Subjective symptoms without a separate diagnosis, such as dizziness, daily headaches, or sensitivity to light or sound, are scored on the same table.

• Emotional/behavioral dysfunction is rated under 38 CFR § 4.130 (the General Rating Formula for Mental Disorders) when it rises to a diagnosed mental disorder, and on the table's neurobehavioral effects facet when it doesn't.

• Physical (including neurological) dysfunction, such as seizures, hearing loss and tinnitus, vision problems, loss of smell and taste, balance problems, or a neurogenic bladder, is rated under the appropriate diagnostic code for each condition and combined.

The 10 facets and how the highest one sets the rating

The table scores 10 facets. Each facet has levels from 0 to 3 plus a fifth level labeled "total," but not every facet has every level. The highest level on any facet sets the table rating.

The notable feature is what's not there: there's no 30%, no 50%, no 60%. The schedule jumps from 10 to 40, from 40 to 70, and from 70 to 100. Those gaps create real money on the table at every threshold.

The facets don't combine using the standard combined-rating math. If memory rates at level 2, judgment at level 1, and orientation at level 3, the table rating is 70%. That table rating then counts as a single condition, and it combines under § 4.25 with any separate rating for a diagnosed mental disorder under § 4.130 or for physical residuals rated under their own codes.

A few details in the table decide a lot of claims. On the memory facet, a complaint of mild memory loss without objective evidence on testing is level 1 (10%); level 2 and above require objective evidence on testing. The subjective symptoms facet tops out at level 2 (40%), so headaches, dizziness and similar symptoms scored there cannot by themselves carry the table past 40%. The symptoms listed at each level are examples, not a checklist (Note (2)). And the "mild," "moderate," and "severe" labels in your medical records describe the injury at the time it happened; under Note (4) they do not affect the DC 8045 rating.

That's the regulatory text. The complication is that two of the three areas (emotional/behavioral and physical) overlap with other diagnostic codes that can sometimes be rated separately.

How much VA pays for TBI

Claim Raven's read does not record which tier the Board assigned, so I can't show how TBI grants spread across the chart. The Board section below shows results by what the appeal asked for, including appeals for a higher rating.

Using VA's rates effective December 1, 2025 (the 2026 rates), a veteran with no dependents is paid the following at each tier the TBI table can produce. If you have other service-connected conditions, VA pays on the combined rating, not on the TBI rating alone.

The structure of the schedule makes 70% a natural landing spot, for the same reason as PTSD. The 100% tier under the DC 8045 table requires at least one of its 10 facets to reach the "total" level. Outside the table, a diagnosed mental disorder rated at 100% under § 4.130 also reaches 100%. Many TBI claims with significant impairment don't clear either bar.

The 70% tier captures veterans with severe but not totally disabling residuals. It also captures veterans whose TBI is being rated under § 4.130 with the PTSD pathway, where 70% is the step below total impairment. And it captures veterans whose highest facet in the DC 8045 table is at level 3, one step below "total," which DC 8045 maps to 70%.

For veterans rated at 70% with significant impairment, TDIU under 38 CFR § 4.16 is the main route to the 100% compensation level without clearing the schedular bar. A 70% TBI rating clears the single-disability TDIU threshold (60% or higher on one disability). If the TBI prevents substantially gainful employment, TDIU pays at the 100% rate even though the schedular rating itself stays at 70%. The gap between the 70% and 100% rates is $2,130.13 per month, or about $25,562 a year, tax-free.

TBI with migraines, PTSD and other overlapping conditions

The pyramiding rule at 38 CFR § 4.14 says VA can't rate the same impairment twice. Note (1) to DC 8045 applies it to TBI: if the manifestations of a TBI and another condition cannot be clearly separated, VA assigns a single evaluation under whichever set of criteria better assesses the overall impaired functioning. If they are clearly separable, each condition gets its own evaluation.

This is the central battleground in TBI cases at the Board. The cleanest way to see it is in the conditions veterans claim as secondary to TBI. In the Board's 2021 to 2026 rulings, migraines and sleep apnea were the conditions most often claimed as secondary to TBI; the Board section below lists the secondary conditions with their counts and grant rates. Each of these is a place where the same symptom can be counted twice, and in the decisions I read, the Board's application varies. Some judges treat a migraine and the TBI table's headache symptoms as completely separable. Others treat them as overlapping and pick one.

TBI and migraines (DC 8100)

Migraines have their own rating ladder under DC 8100: 0%, 10%, 30% and 50%, based on how often "prostrating" attacks occur and how severe they are. DC 8045 itself says to evaluate a residual with a distinct diagnosis, such as migraine headache, separately under its own code rather than under the TBI table, even when that diagnosis rests on subjective symptoms.

So a VA rating for TBI with migraines usually means two ratings: the migraine under DC 8100 and the TBI table for the other residuals. The rule is that the same headache symptoms cannot also support the TBI table's subjective symptoms facet. The two ratings then combine using the standard combined-rating math at 38 CFR § 4.25. The question in practice is whether the headaches have been pulled out of the TBI table once they are rated as migraine.

TBI and PTSD: the DC 8045-9411 code

Under the DC 8045 framework, emotional and behavioral dysfunction is rated under 38 CFR § 4.130 when it rises to a diagnosable mental disorder. That's the route by which PTSD secondary to TBI, or co-occurring with TBI, gets rated. The rating is computed once under § 4.130 (usually as PTSD at DC 9411) and the TBI's emotional side folds into that rating. The cognitive and physical residuals of the TBI are then rated separately if they produce impairment beyond what the psychiatric rating captures.

The hyphenated code DC 8045-9411 is the visible artifact of that choice. Under 38 CFR § 4.27, a hyphenated code lists the underlying condition first and, after the hyphen, the code for the residual whose criteria actually set the rating. For DC 8045-9411, the rater is rating the TBI residuals (DC 8045) under the criteria of DC 9411, which is the General Rating Formula for Mental Disorders.

For veterans whose file has both TBI residuals and PTSD, the strategic question is whether to push for one rating under § 4.130 or for separate DC 8045 and DC 9411 ratings (which combine under § 4.25). The answer depends on the symptom picture. If the cognitive, emotional, and physical problems are genuinely distinct, separate ratings can produce a higher combined total. If the impairments substantially overlap, a single rating is usually where the case settles. This is one of the more technical rating mechanics in the schedule, and getting the symptom attribution right can change the combined rating.

Conditions secondary to TBI under 38 CFR § 3.310(d)

A rule published in December 2013 added 38 CFR § 3.310(d), which holds five groups of conditions to be the result of a service-connected TBI unless there is clear evidence to the contrary. Each comes with a TBI severity requirement, and some with a time limit.

Severity here is set by the TBI's symptoms at the time of injury or shortly after, not by how you function today. VA does not require every criterion at a level; it ranks the TBI at the highest level where any one criterion is met.

Missing the severity level or the time limit does not end the claim. Section 3.310(d)(2) says VA will then decide it under the ordinary rules of service connection. The same ordinary rules cover conditions not on the list, such as migraines and sleep apnea: you need a medical opinion that the TBI caused the condition, or aggravated it, meaning the condition would be less severe but for the TBI. Related pages cover Parkinson's disease, epilepsy and seizures and depression.

How to prove a TBI is service connected

A TBI claim has three parts: a current diagnosis of TBI or its residuals, evidence of the head injury in service, and a link between the two. For TBI, the first two are usually where the claim is won or lost.

Showing the head injury happened in service

The cases that get past this hurdle usually have one of three things.

A documented in-service event. Line-of-duty determinations, accident reports, sick call entries describing the incident, witness statements. Post-9/11 IED-blast events often have these. Vietnam-era veterans rarely do.

A medical record that survived. Service treatment records that mention a head injury, sick call slips, or a medical history form completed at separation where you reported a head injury.

Statements from people who were there. A buddy statement about an IED blast, a vehicle accident, or a fall can fill the gap when the official record is thin.

For veterans without any of these, the in-service injury is hard to prove, and combat service changes the rules.

Combat veterans and 38 USC § 1154(b)

Under 38 USC § 1154(b) and 38 CFR § 3.304(d), if you engaged in combat with the enemy, VA has to accept satisfactory lay evidence that an injury happened in combat when it is consistent with the circumstances, conditions, or hardships of that service, even with no official record. VA can rebut it only with clear and convincing evidence. For many combat-era TBI claims, the event is the central obstacle, so this matters. It proves the event only. It does not establish the TBI diagnosis or the link to current residuals, and veterans whose records don't capture the blast or impact should invoke it explicitly.

A TBI diagnosis years after the injury

A traumatic brain injury's severity is judged by markers recorded at or near the time of injury: loss of consciousness, altered consciousness, post-traumatic amnesia, the Glasgow Coma Scale, and imaging. Section 3.310(d)(3) and Note (4) to DC 8045 both tie severity to that window.

For combat-era veterans, the contemporaneous record often doesn't exist. A soldier who got concussed by an IED blast, walked it off, and went back to work didn't get a Glasgow Coma Scale documented. The medic might have written "blast exposure, returned to duty" if anything was written at all. Years later, when the veteran files a claim for cognitive impairment, sleep disruption, mood changes, and headaches, the diagnostic anchor for "yes, this was a TBI" is gone.

VA clinicians do diagnose mild TBI years later from a structured history of the injury. But a study of post-9/11 veterans found that VA's Comprehensive TBI Evaluation and a validated research interview often disagreed about who had a mild TBI, which shows how hard a diagnosis from memory is (Radigan, Journal of Head Trauma Rehabilitation, 2018). The symptoms also overlap with other conditions. In an Army survey of soldiers back from Iraq and Afghanistan, symptoms such as headaches were more strongly associated with PTSD and depression than with a history of concussion (Wilk, Psychosomatic Medicine, 2012). A C&P examiner can point to those overlaps as alternative explanations.

That is why the quality of the diagnosis matters. A primary care note that says "history of TBI" is weaker than a neuropsychological evaluation that documents cognitive deficits on testing and ties them back to the in-service event.

Why the link to service is rarely the fight

For TBI, the central evidence question is often whether the injury happened, and whether its residuals can be shown today, not whether the current condition is connected to it. If a veteran was hit by an IED blast in 2007 and now has cognitive impairment, the link from blast to impairment isn't usually in dispute. What's in dispute is whether the blast produced a clinically diagnosable TBI. The Board data fits that: when it denied TBI service connection, a missing link to service was the least common of the three reasons it gave. Many TBI appeals are not about service connection at all but about the rating, and the Board section below shows results by what the appeal asked for.

The medical opinion still matters when it applies. Among TBI claims the Board granted or denied, those with a private medical opinion in the record were granted more often than TBI claims overall, an association rather than a cause. The Board section below shows how the Board ruled when it relied on a favorable medical opinion, an opinion against the claim, or none.

The TBI C&P exam

VA lists its "Initial Evaluation of Residuals of Traumatic Brain Injury" and "Review Evaluation of Residuals of Traumatic Brain Injury" questionnaires among the DBQs that are not available for public use, citing limits in federal regulations and the specialized training needed to complete them. So you can't bring a completed TBI questionnaire from your own doctor. Your own doctor's records, testing, and opinions still count as evidence.

The exam matters because the rating follows the examiner's facet-by-facet findings. The strongest TBI files have a C&P or private opinion that walks through each area of DC 8045 and attributes specific impairment to each: cognitive deficits documented through testing, emotional and behavioral symptoms characterized either as a diagnosable mental disorder (for a § 4.130 rating) or as TBI residuals scored on the table, and physical residuals documented under their own codes where appropriate (DC 8100 for migraine, and so on).

Symptom attribution is where many claims turn. An examiner who writes "the veteran's depressed mood, sleep disturbance, and irritability are best attributed to PTSD; the cognitive impairment is best attributed to TBI" sets up a cleaner rating analysis than one who writes "the veteran has TBI and PTSD with overlapping symptoms." Where TBI and PTSD coexist, the strongest claims address the overlap on the front end rather than letting the examiner default to whatever framework feels easiest.

Before the exam, write down how each problem shows up in a normal week: memory lapses, getting lost, headaches that force you to rest, irritability at work, trouble finding words. A symptom tracker kept for a few weeks gives the examiner frequency instead of impressions, and C&P exam prep helps you organize it. Bring or upload any neuropsychological testing, since objective testing is what moves the memory facet past level 1.

Why VA denies TBI claims

The first thing the 8,367 decided Board rulings on TBI tell me is that the Board is harder on TBI claims than it is on the typical claim.

The outcome split is below.

• Granted: 1,480 rulings (17.7%)
• Denied: 2,799 rulings (33.5%)
• Remanded: 4,088 rulings (48.9%)
• Dismissed or withdrawn: 880 rulings, left out of the grant rate because the Board never decided them

Across all 1,241,238 decided rulings in Claim Raven's read, the Board-wide split is a grant in 24.7%, a denial in 30.0% and a remand in 45.3%. TBI's grant rate is 7 points below the Board-wide 24.7 percent. Its denial rate is 3.5 points above, and its remand rate 3.6 points above. Both of the outcomes that aren't grants run higher for TBI.

When the Board denied TBI service connection, the most common reason by a wide margin was that the record did not show a current diagnosed disability. The second was no proof of the in-service injury. The patterns behind those denials repeat.

No current diagnosed disability. The exam finds no TBI residuals, or the record shows symptoms without a TBI diagnosis. Memory complaints without testing, headaches attributed to something else, or a screening result that was never followed by a full evaluation all end up here.

No record of the head injury. Service records are silent, there is no combat service to bring in § 1154(b), and no one who was there has written a statement.

Symptoms attributed to another condition. The examiner ties the cognitive and mood symptoms to PTSD, depression, sleep problems, chronic pain, or aging instead of the TBI.

A secondary opinion that skips aggravation. For a condition claimed secondary to TBI that is not on the § 3.310(d) list, an opinion that says only "not caused by" the TBI, without addressing whether the TBI made the condition worse, is inadequate (El-Amin v. Shinseki, 26 Vet. App. 136 (2013)).

The rating level isn't shown. On a rating appeal, the record has to show the facet level. The memory facet needs objective testing above level 1, and the other facets turn on a clear account of how often the problem happens and how much it interferes with work and daily life.

When the Board sent a TBI claim back instead of deciding it, the most common reason was an inadequate VA exam or opinion, followed by records VA still had to get. The Board section below shows how often each denial and remand reason came up, and what happened after a remand when the Board decided the appeal again.

Questions veterans ask about TBI

What is the highest VA rating for TBI?

100 percent. Under DC 8045, VA assigns 100 percent when any facet of the TBI table is at the "total" level. Below that, the table tops out at 70 percent, but separately rated residuals such as a mental disorder or migraines combine with it, and DC 8045 tells VA to consider special monthly compensation for problems such as the need for aid and attendance.

Can you get a VA rating for TBI and migraines?

Yes. DC 8045 says a residual with its own diagnosis, such as migraine headache, is rated separately under its own code, here DC 8100 at 0, 10, 30 or 50 percent. The same headaches cannot also count on the TBI table's subjective symptoms facet, and the two ratings combine under 38 CFR § 4.25.

Is TBI a presumptive condition for VA?

No. There is no presumption that a diagnosed TBI came from service, so you have to show the injury happened. Combat veterans get an easier way to prove the injury under 38 USC § 1154(b), and the Gulf War rule in 38 USC § 1117 (carried out by 38 CFR § 3.317) covers undiagnosed illnesses and medically unexplained chronic multisymptom illnesses, not a diagnosed TBI. Once a TBI is service connected, 38 CFR § 3.310(d) presumes certain later conditions are secondary to it.

What conditions are secondary to TBI?

Under 38 CFR § 3.310(d), VA holds Parkinsonism, unprovoked seizures, certain dementias, depression and some hormone deficiency diseases to be secondary to a service-connected TBI when they meet the rule's severity and time limits. Other conditions, such as migraines and sleep apnea, need a medical opinion that the TBI caused or worsened them.

Does a mild, moderate or severe TBI change the VA rating?

Not under DC 8045. Note (4) to the code says those labels describe the injury at the time it happened, not your current functioning, and they do not affect the rating. They do matter under 38 CFR § 3.310(d), where most of the presumed secondary conditions require a moderate or severe TBI.

Can VA rate TBI and PTSD separately?

Yes, when the symptoms can be clearly separated. If the TBI and PTSD symptoms overlap so they cannot be separated, VA assigns a single rating under whichever criteria better capture the combined impairment, often written as DC 8045-9411.

Bottom Line

TBI is rated under 38 CFR § 4.124a, Diagnostic Code 8045, using a framework of three areas (cognitive, emotional/behavioral, physical). The highest-rated facet in the TBI table sets that rating at tiers of 0/10/40/70/100, while a diagnosed mental disorder and physical residuals are rated under their own codes. Across 8,367 decided Board rulings on TBI from 2021 to 2026, 17.7% were granted, 33.5% denied and 48.9% remanded, a grant rate 7 points below the Board-wide 24.7%. The structural reasons are particular to this condition: TBI is hard to document years after the injury, so whether the record shows a diagnosed disability and the in-service injury carries much of the claim, and the pyramiding analysis under 38 CFR § 4.14 for overlapping PTSD, migraine, and depression symptoms turns many cases on how the symptom attribution is handled. The combination code DC 8045-9411 is how VA rates TBI residuals under the mental disorder criteria when the two can't be separated. Once a TBI is service connected, 38 CFR § 3.310(d) presumes certain later conditions are secondary to it. The 70 percent rating is a natural landing spot because the leap to 100 percent requires total impairment under either DC 8045's facet criteria or 38 CFR § 4.130's mental health framework, and TDIU under 38 CFR § 4.16 is the main path to 100 percent compensation for veterans rated at 70 percent whose residuals prevent substantially gainful employment. Using rates effective December 1, 2025 (the 2026 rates), the gap between 70 percent and 100 percent for a veteran with no dependents is $2,130.13 per month. The single most useful thing a veteran can do for a TBI claim is invest in the documentation of the in-service event and the diagnosis, because the rating mechanics will produce a meaningful outcome once those two questions are answered.

Methodology and Limitations

• Data source: Outcome statistics and the denial, remand and secondary-condition patterns are drawn from Claim Raven's read of 511,036 Board decisions from 2021 to 2026, which contain 1,378,030 rulings, including 9,247 rulings on TBI. Claim Raven's full library holds 1,871,000+ Board decisions. Rating framework is drawn from 38 CFR § 4.124a, Diagnostic Code 8045 (revised October 2008), and Diagnostic Code 8100 for migraine. Mental disorder rating framework is drawn from 38 CFR § 4.130. Pyramiding rule is at 38 CFR § 4.14, hyphenated codes at § 4.27, combined ratings math at § 4.25. TBI secondary conditions and severity levels at 38 CFR § 3.310(d). Combat rule at 38 USC § 1154(b) and 38 CFR § 3.304(d). Gulf War rule at 38 USC § 1117, as amended by the PACT Act in 2022, and 38 CFR § 3.317, which has not yet been rewritten to match the statute. TDIU at 38 CFR § 4.16. VA disability compensation rates effective December 1, 2025 (the 2026 rates). The DBQ availability is from VA's public DBQ list. The studies cited are Radigan, "Correspondence of the Boston Assessment of Traumatic Brain Injury-Lifetime and the VA Comprehensive TBI Evaluation," Journal of Head Trauma Rehabilitation (2018), and Wilk, "Mild traumatic brain injury (concussion), posttraumatic stress disorder, and depression in U.S. soldiers involved in combat deployments," Psychosomatic Medicine (2012).
• Sample size: 8,367 decided Board rulings on TBI, with outcomes split 17.7% granted (1,480), 33.5% denied (2,799) and 48.9% remanded (4,088). Another 880 rulings were dismissed or withdrawn and are left out of the grant rate.
• Classification approach: Denial and remand reasons are read from each ruling; one denial can rest on more than one reason. Secondary-condition counts are service connection rulings whose order names TBI after "secondary to" or similar wording. The read does not record the rating tier assigned, so this page does not report a tier distribution.
• Regulation currency: VA's November 2024 proposal to revise the neurological rating schedule (89 FR 88917, RIN 2900-AQ73) describes only non-substantive changes to DC 8045, moving its table to sit directly below the code. It was still a proposal when this page was checked in early October 2026.
• Limitations:
• These rulings reached the Board, not all TBI claims filed with VA. Claims granted at the regional office without appeal aren't in this data.
• TBI severity (mild, moderate, severe) is not cleanly coded in the dataset. Severity does not change the DC 8045 rating, but it does decide whether the § 3.310(d) presumptions apply, and a mild TBI with significant late-onset symptoms can rate the same as a moderate TBI with milder current residuals.
• Some veterans with TBI residuals are rated entirely under DC 9411 (PTSD) or other diagnostic codes, without a DC 8045 rating. Those cases appear in the dataset as PTSD cases rather than TBI cases, even though TBI is part of the medical history.
• The dataset doesn't capture how closely C&P examiners follow VA's TBI exam protocol. Examiner quality varies a lot in the decisions I read, but I can't quantify the variation as a clean variable. It also doesn't show what happens when a veteran refiles after a denial.
• The pyramiding analysis under § 4.14 is applied differently across judges. The DC 8045-9411 combination code is one resolution; the data doesn't capture how often a different resolution would have produced a higher rating.
• Private-opinion figures are associations, not causes.
• These observations reflect BVA patterns. They are not predictions of individual outcomes. TBI cases turn on file-specific evidence, examiner quality, and the application of overlapping diagnostic codes, all of which vary widely.