ModifiedEmblemHealthPolicy AHS-G2151

Serum Testing for Evidence of Mild Traumatic Brain Injury

Defines EmblemHealth's reimbursement stance on serum biomarker testing (e.g., S100B, GFAP, UCH-L1) for evaluation of mild traumatic brain injury (mTBI) and explains applicability to claims processing and provider billing.

Policy Summary

PayerEmblemHealth

PolicySerum Testing for Evidence of Mild Traumatic Brain Injury

Policy CodePolicy AHS-G2151

Change TypeCoverage clarification — panels reassigned to CC2background and formatting updates

Effective DateMar 15, 2025

Next Review Date

Key ActionDo not bill for panel assays measuring multiple TBI biomarkers; these panels do not meet coverage and may be denied or recouped.

SourceLink

POLICY UPDATE CHANGES

Panel testing moved from CC1 into new CC2 for clarity and panels designed to measure biomarkers of TBI (e.g., i-STAT TBI Plasma, Alinity) DO NOT MEET COVERAGE.

Updated background, guidelines and recommendations, and evidence-based scientific references; literature review did not necessitate any modifications to coverage criteria.

Transferred policy content to individual company-branded template and reformatted/reorganized the policy into a new template with a new reimbursement policy number.

Not coveredserum concussion marker testing for evaluation of mTBI

1coverage category clarified (CC2 for panel testing)

Adults ≤12hintended use population/timing for cleared tests

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.

95.8%i-STAT reported sensitivity

83516example CPT code

.62-.89GFAP/UCH-L1 prognostic AUCs

Coverage Criteria and Exclusions

Coding and Procedural References

Applicable coding guidancemixed

No codes listed

Procedural code referenceCPT

83516

Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semiquantitative, multiple step method

Non-covered panel testsmixedNot Covered

No codes listed

UCH-L1 cutoff cited in study (inv-07)

UCH-L1 cutoff (study)>40 pg/mL — reported 100% sensitivity and 39% specificity in one cohort (Welch et al., measured within 6 h)

ImplicationValues <40 pg/mL could have aided elimination of CT scans in a subset of negative CT patients in the cited cohort

Context of measurementBiomarkers measured within 6 hours of injury in the referenced study

S100B guideline cutoff referenced (inv-08)

S100B guideline cutoff0.1 µg/L — guideline-referenced cutoff used to reduce need for CT in initial management of mild TBI

Performance in validationMulticenter validation: 97% sensitivity and 34% specificity for identifying CT-positive intracranial hemorrhage

Timing/applicationUsed in acute evaluation; some guidance applies within 4 hours of injury for initial management

Coverage threshold (inv-09)

Coverage designation for panel assaysPanel assays for TBI biomarkers are designated as not covered and assigned to Coverage Category 2 (CC2)

Examples of affected panelsPanels designed to measure biomarkers of TBI (e.g., i-STAT TBI Plasma, Alinity) do not meet coverage

Operational changePanel testing moved from CC1 into new CC2 for clarity in the revision history

Provider Actions, Billing, and Operational Notes

Denial Risk

Claims editing and enforcement

Claims may be denied or recouped if appropriate coding/billing guidelines or current reimbursement policies are not followed. Providers should follow CPT, CMS/NCCI, and other industry-standard coding guidance and be prepared to provide documentation or explanation of coding decisions upon request.

Follow industry-standard coding guidance (AMA CPT, CMS NCCI/MUE).
Use approved claims-editing software outputs and local payer guidance when applicable.
Be prepared to support coding decisions and documentation if a claim is reviewed.

Note

Coverage determination (no coverage)

Measurement of concussion biomarkers (e.g., S100B, GFAP, and UCH-L1) in blood, saliva, or cerebrospinal fluid (CSF) for the evaluation of mild traumatic brain injury (mTBI) does not meet coverage criteria due to insufficient evidence that these tests are required and beneficial for diagnosis or treatment.

Includes testing of S100B, GFAP, UCH-L1 in blood, saliva, or CSF.

Definitions and Biomarker Terms

GFAP — definition (inv-14)

TermGFAP — Glial fibrillary acidic protein

RoleMarker suggested to reflect astroglial injury and focal intracranial lesions (see policy background)

ContextReferenced among biomarkers studied for detection and prognosis of TBI

mTBI — definition (inv-15)

TermmTBI — Mild traumatic brain injury

ScopeUsed throughout policy to describe the target clinical condition for serum biomarker evaluation

Clinical range

Policy Summary

PayerEmblemHealth

PolicySerum Testing for Evidence of Mild Traumatic Brain Injury

Policy CodePolicy AHS-G2151

Change TypeCoverage clarification — panels reassigned to CC2background and formatting updates

Effective DateMar 15, 2025

Next Review Date

Key ActionDo not bill for panel assays measuring multiple TBI biomarkers; these panels do not meet coverage and may be denied or recouped.

SourceLink

On This Page

These tests are considered not covered for evaluation of mild TBI per policy CC1.

Documentation Required

Regulatory and operational notes

Labs may perform validated laboratory-developed tests (LDTs) under CLIA as high-complexity tests; LDTs are not FDA-cleared or approved but are permitted for clinical use when validated by the performing laboratory. FDA-cleared/approved tests include Abbott's i-STAT TBI Plasma Cartridge for use with the i-STAT Alinity system (510(k) cleared Jan 8, 2021) and Abbott's Alinity TBI lab test (approved March 2023) which measure UCH-L1 and GFAP and are intended for use in adults (18+) with suspected mTBI within 12 hours to aid imaging decisions. Providers should note the intended use limitations and payer coverage determination when ordering or billing for these assays.

Laboratory-developed tests (LDTs) are regulated under CLIA as high-complexity tests and are performed/validated in-house by the lab.
FDA-cleared/approved assays: i-STAT TBI Plasma Cartridge (i-STAT Alinity system) — intended for patients ≥18 years with suspected mTBI (GCS 13-15) within 12 hours to aid imaging decisions.
Abbott Alinity TBI lab test measures UCH-L1 and GFAP; intended as complement to i-STAT Alinity system; note age and time-since-injury limitations.

Billing Rule

Coverage exclusion for panel tests

Panels designed to measure biomarkers of TBI (for example, i-STAT TBI Plasma panel and Alinity TBI panel) do not meet coverage under new CC2 and should not be billed as covered panel tests.

Panel tests that combine multiple TBI biomarkers are considered not covered per CC2.
Do not bill panels (e.g., i-STAT TBI Plasma, Alinity TBI panels) as covered services.

Typically corresponds to Glasgow Coma Scale scores 13–15 in FDA-cleared intended use statements

UCH-L1 — definition (inv-16)

TermUCH-L1 — Ubiquitin C-terminal hydrolase-L1

AssociationDescribed as a protease-related biomarker suggestive of diffuse axonal injury and complementary to GFAP

Use in cleared testsMeasured by FDA-cleared assays (e.g., Abbott Alinity and i-STAT) as part of TBI biomarker assessment

S100B — definition (inv-17)

TermS100B — S100 calcium-binding protein B

BiologyExpressed in astrocytes; present in bloodstream when blood–brain barrier disrupted

LimitationsNot brain-specific; elevated in extracranial trauma and non-neural tissues, limiting utility in multiple-trauma settings

GFAP — clinical meaning (inv-18)

DescriptionGlial fibrillary acidic protein (GFAP) — a blood biomarker suggested to indicate focal lesions and intracranial bleeding

Comparative noteMay be more specific for intracranial lesions than S100B but may be less sensitive to axonal injury

Clinical implicationOften considered complementary to UCH-L1 for broader assessment of injury types

UCH-L1 — clinical meaning (inv-19)

DescriptionUbiquitin C-terminal hydrolase L1 (UCH-L1) — a protease-related biomarker associated with diffuse axonal injury

Complementary roleTogether with GFAP, provides complementary information reflecting different pathophysiological mechanisms

Evidence citeReferenced studies indicate UCH-L1 may outperform GFAP and S100B when goal is to reduce CT use without sacrificing sensitivity in some cohorts

Laboratory‑developed test (LDT) — definition (inv-20)

DefinitionLaboratory-developed test (LDT) — a test developed and validated within a laboratory and regulated under CLIA as high-complexity testing (not FDA-cleared)

Regulatory noteLDTs are regulated by CMS under CLIA '88 and are not FDA approved/cleared for clinical use, though they may be used clinically

Operational relevancePolicy notes LDTs may be performed in-house but distinguishes them from FDA-cleared platform tests

TBI biomarkers — overview (inv-21)

ScopeTBI biomarkers — biomarkers referenced include GFAP, UCH-L1, S100B and others studied to detect or prognosticate traumatic brain injury

PurposeStudied for diagnosis, prognostication, and potential to inform imaging decisions in mTBI

Evidence statusEvidence is variable; guidelines and studies report differing sensitivity/specificity and cautious recommendations from professional bodies

CC2 (panel testing) — definition (inv-22)

Coverage categoryCC2 — Coverage Category 2: panels designed to measure biomarkers of TBI do not meet coverage

Policy actionPanel testing moved from CC1 into new CC2 to clarify non-coverage of TBI biomarker panels

ExamplesSpecifically calls out i-STAT TBI Plasma and Alinity panels as not meeting coverage under CC2