CurrentBlue Cross Blue Shield - TennesseePolicy N/A

Immunohistochemistry (IHC) — Coding and Reimbursement Guidance

This policy describes immunohistochemistry (IHC) as a laboratory technique, reimbursement coding guidance for IHC procedures (CPT codes 88341, 88342, 88344), and coverage considerations tied to members' benefit plans and applicable government policies. It affects providers submitting IHC tests for Blue Cross Blue Shield of Tennessee members.

Policy Summary

PayerBlue Cross Blue Shield - Tennessee

PolicyImmunohistochemistry (IHC) — Coding and Reimbursement Guidance

Policy CodePolicy N/A

Change TypeNo material change

Effective DateN/A

Next Review DateN/A

Key ActionUse code 88342 for the first single antibody procedure (1 unit per specimen, up to 4 specimens/day); use 88341 for additional single antibody stains and 88344 for multiplex stains, applying member benefit coverage and applicable government policies.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

88342 = 1/unitinitial single antibody

88341 = up to 13additional single antibody

88344 = up to 6multiplex antibody

88341,88342,88344CPT codes referenced

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 and limits

Coverage and reimbursement for immunohistochemistry (IHC) are governed by the member's benefit coverage and applicable state/federal policies; coding and unit limits below apply when services are covered.

Coverage decisions are dependent upon an individual member's benefit coverage at the time of the request; applicable Medicare/Medicaid (LCD/NCD/state) policies supersede this policy if there is a conflict.

Coding and reimbursement limits

Use CPT 88342 for the first single antibody procedure; reimbursed at one unit per specimen, up to 4 specimens per date of service.
Use CPT 88341 for each additional single antibody per specimen; reimbursed up to a maximum of 13 units per date of service.
Use CPT 88344 for each multiplex antibody per specimen; reimbursed up to 6 specimens per date of service.

CPT Codes, Descriptions, and Reimbursement Limits

IHC CPT codes and descriptionsCPTCovered

88342	Immunohistochemistry or immunocytochemistry, per spec; initial single antibody stain.
88341	Immunohistochemistry or immunocytochemistry, per specimen; each additional single antibody stain procedure.
88344	Immunohistochemistry or immunocytochemistry, per specimen; each multiplex antibody stain procedure.

Maximum reimbursable units per date of service

88342Use for the first single antibody procedure; reimbursed at 1 unit per specimen, up to 4 specimens per date of service.

88341Use for each additional single antibody per specimen; reimbursed up to a maximum of 13 units per date of service.

88344Use for each multiplex antibody per specimen; reimbursed for up to 6 specimens per date of service.

Billing and Provider Guidance

Billing Rule

Billing and prior authorization guidance for IHC (88342/88341/88344)

Use CPT code 88342 for the first single antibody IHC procedure and bill one unit per specimen, up to four specimens per date of service. For additional single antibody stains, bill CPT code 88341 — reimbursed up to a maximum of 13 units per date of service. For multiplex antibody stains, bill CPT code 88344 — reimbursed up to six specimens per date of service. Confirm member benefit coverage and follow applicable government (LCD/NCD) policy when it conflicts with this policy.

88342: initial single antibody stain — 1 unit per specimen, up to 4 specimens per date of service.
88341: each additional single antibody stain — reimbursed up to 13 units per date of service.
88344: each multiplex antibody stain — up to 6 specimens per date of service.
When government policies (e.g., LCDs/NCDs) conflict with this policy, the government policy prevails.

Key Terms

Immunohistochemistry (IHC)

DefinitionA very sensitive and specific staining technique that uses anatomical, biochemical, and immunological methods to identify cells, tissues, and organisms by the interaction of target antigens with highly specific monoclonal antibodies and visualization through a biochemical tag or label.

PurposeUsed to detect target antigens for identification of cells, tissues, and organisms; supports diagnostic and therapeutic decisions when used with other molecular tests.

Key componentsUses highly specific monoclonal antibodies and a biochemical tag or label for visualization.

Laboratory‑developed test (LDT)

DefinitionLaboratory-developed tests (LDTs) are tests developed and validated in-house by laboratories and are regulated by CMS as high-complexity tests under CLIA.

FDA statusLDTs are not approved or cleared by the U.S. Food and Drug Administration; FDA clearance or approval is not currently required for clinical use.

Clinical use exampleSome IHC biomarker assays (PTEN, RB, MLH1, MSH2) have been validated in clinical trials and were approved by the FDA as LDTs to assist treatment selection, demonstrating clinical utility of LDT IHC assays.