CurrentCapital BluecrossPolicy AHS - G2151 - Serum Testing for Evidence of Mild Traumatic Brain Injury, 1 = Initial Presentation

Serum Testing for Evidence of Mild Traumatic Brain Injury

Defines coverage stance for blood (and other fluid) biomarkers (e.g., S100B, GFAP, UCH-L1) and associated panels/devices for evaluation of suspected mild traumatic brain injury; affects providers ordering or billing these tests for Capital BlueCross members.

Policy Summary

PayerCapital Bluecross

PolicySerum Testing for Evidence of Mild Traumatic Brain Injury

Policy CodePolicy AHS - G2151 - Serum Testing for Evidence of Mild Traumatic Brain Injury, 1 = Initial Presentation

Change TypeNo material changes

Effective DateApr 19, 2018

Next Review Date

Key ActionDo not order or expect coverage for measurement of concussion biomarkers (e.g., S100B, GFAP, UCH-L1) or biomarker panels for evaluation of mild TBI because they do not meet coverage criteria.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

32%estimated CT reduction

75%mild TBI proportion

95.8%i-STAT sensitivity

96.7%Alinity sensitivity

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Coverage Criteria

Not medically necessary / Not covered

Not covered when any of the following apply:

Not covered uses: Measurement of concussion markers (e.g., S100B, GFAP, UCH-L1) in blood, saliva, and/or cerebrospinal fluid for evaluation of mild traumatic brain injury.

Does not meet coverage criteria due to lack of sufficient published scientific literature confirming that the test(s) are required and beneficial for diagnosis and treatment; applies to single biomarkers in any fluid source.

Not covered panels/devices: Panels or proprietary platforms designed to measure biomarkers of TBI (for example, i-STAT TBI Plasma, Alinity® i TBI).

These panels and devices do not meet coverage criteria.

Clinical utility and intended use statements

Summarized positions from multiple organizations:

Professional society consensus on biomarkers: Multiple organizations (VA/DoD; ACSM/AAFP/AAOS/AMSSM/AOSSM/AOASM; AAP; AMSSM; 6th International Consensus) state that fluid biomarkers are investigational, have low or inconclusive evidence, or their role in guiding clinical management remains unclear.

Professional bodies note limited or low-quality evidence and recommend further study; biomarkers are not established for routine diagnosis/management.

Scandinavian guideline S100B use: Scandinavian Neurotrauma Committee recommends S100B <0.10 mg/L within 6 hours in certain adult patients to help rule out the need for CT imaging.S100B <0.10 mg/L within 6 hours

Applies to adults <65 with GCS 14 or GCS 15 with loss of consciousness or repeated vomiting; incremental value over established decision rules is unknown.

FDA-cleared tests intended use: FDA-cleared i-STAT TBI and Alinity® i TBI are intended to aid evaluation of adults (≥18 years) with suspected mTBI (GCS 13-15) within 12 hours of injury to assist assessment of need for CT imaging; not intended for point-of-care use (i-STAT result associated with absence/presence of acute traumatic intracranial lesions on CT).Age >= 18; GCS 13-15; within 12 hours of injury

FDA clearance does not by itself establish coverage; tests must be used as indicated by their intended use statements.

Limitations and pediatric data: Several organizations note insufficient pediatric data and unclear incremental value of biomarkers compared with established clinical decision rules for CT use or diagnosis; no objective biomarker is established to determine mTBI resolution.

Use in children and adolescents may differ due to developmental factors; clinical decision rules remain primary.

Panels designed to measure biomarkers of traumatic brain injury (TBI) — including proprietary platforms such as the i-STAT TBI Plasma and Alinity® i TBI — do not meet coverage criteria for evaluation of mild TBI and are explicitly excluded from coverage per the policy. This exclusion applies to panels intended to measure concussion markers (for example, GFAP and UCH-L1) as part of a multi-analyte panel.

Major professional organizations and guideline bodies indicate that fluid biomarkers are not established for routine diagnosis or management of concussion. The VA/DoD guideline specifically recommends against using serum biomarkers (including S100-B, GFAP, and UCH-L1) to establish mTBI diagnosis or direct care. Similarly, sports medicine societies and the AAP characterize the evidence as low or inconclusive and note these biomarkers currently have no role in routine clinical management. The 6th International Consensus (Amsterdam 2023) states that their role in guiding individual clinical management remains unclear, particularly in children and adolescents.

Several citations in the evidence section and guideline lists are referenced for background and context, but these particular references do not themselves state additional explicit coverage exclusions beyond those summarized in this policy. They are provided as supporting literature and guideline sources.

Measurement of concussion biomarkers such as S100B, GFAP, and UCH-L1 in blood, saliva, and/or cerebrospinal fluid (CSF) does not meet coverage criteria for the evaluation of mild traumatic brain injury according to this policy, based on insufficient published evidence demonstrating clinical benefit for diagnosis or treatment.

Professional society statements summarize the current evidence as inconclusive or of low quality, and several groups explicitly state biomarkers currently have no role in routine diagnosis or management of sports-related or pediatric concussion. These statements reinforce the policy position that biomarkers presently lack sufficient clinical utility to support coverage for routine use.

Within the set of cited references there are no additional explicit statements labeling these tests as 'not medically necessary.' Those determinations are made in this policy based on the synthesized guidance and available evidence cited elsewhere in the document.

Coding

Applicable CPT/HCPCS procedure codesmixed

No codes listed

Applicable CPT/HCPCS Procedure Codesmixed

83516	Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semiquantitative, multiple step method.
84999	Unlisted chemistry procedure.
0570U	Neurology (traumatic brain injury), analysis of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), immunoassay, whole blood or plasma, individual components reported with the overall result of elevated or non-elevated based on threshold comparison. Proprietary test: i-STAT TBI; Lab/Manufacturer: Abbott Point of Care.

S100B cutoff used in ACEP guidance

ACEP S100B cutoff< 0.1 μg/L measured within 4 hours of injury

ACEP contextConsideration given to not performing CT (Level C) in mild TBI patients without significant extracranial injuries when S100B below cutoff

Intended populationAdults presenting with mild TBI features evaluated in ED per ACEP policy

UCH-L1 cutoff reported in Welch et al.

Welch et al. UCH-L1 cutoff> 40 pg/mL (cutoff at which UCH-L1 was 100% sensitive in the study)

Study performance noteAt >40 pg/mL UCH-L1 had 100% sensitivity and 39% specificity in differentiating CT-positive vs CT-negative

Provider Actions and Authorization

Note

Conflict with government coverage

If there is a conflict between this policy and any applicable government policy for a particular member (for example, Medicare Local Coverage Determinations (LCDs), National Coverage Determinations (NCDs), or state Medicaid policies), the government policy will govern the coverage determination for that member.

Medicare/NCDs/LCDs and state Medicaid policies take precedence when discrepant.

Documentation Required

This section provides citations and does

This section provides citations to applicable state and federal regulations and FDA information relevant to TBI biomarker testing. It does not by itself create or specify authorization or denial criteria.

Links and references to Medicare coverage database and state Medicaid sites are provided for up-to-date government policy.
FDA clearance history for Abbott i-STAT TBI Plasma Cartridge and Alinity® i TBI is cited.

Background

Traumatic brain injury (TBI) results from external mechanical forces and can produce a spectrum of brain injury severity. The majority of TBIs are mild, and clinical evaluation — including neurological assessment and neuroimaging when indicated — remains the standard for diagnosis and triage. Blood-based biomarkers (for example, S100B, GFAP, and UCH-L1) have been investigated as adjuncts to identify intracranial injury and potentially reduce CT utilization, but evidence is variable and does not currently support routine use; accordingly, measurement of these markers is not covered under this policy.

Definitions and Test Descriptions

GFAP

DefinitionGlial fibrillary acidic protein (GFAP): a glial filament protein released after astrocyte injury.

AbbreviationGFAP

Clinical relevanceInvestigated as a blood biomarker for detection of intracranial injury after TBI

S100B

DefinitionS100B: S100 calcium-binding protein B, expressed in astrocytes and present in blood when the blood–brain barrier is disrupted; not brain-specific.

AbbreviationS100B

Clinical relevance