Summary & Overview
CPT 88342: Single-Antibody Immunohistochemistry with Pathologist Interpretation
CPT code 88342 denotes an initial single-antibody immunohistochemical stain performed on slide(s) from a single patient specimen with subsequent interpretation by a qualified provider, most often a pathologist. This code is central to diagnostic workups in oncology and other surgical pathology contexts because immunohistochemistry helps determine tumor origin, subtype, and therapeutic targets, influencing clinical decisions and downstream care.
The analysis covers major national payers including Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find concise benchmarking and policy context for billing and coverage of single-antibody immunohistochemistry services, clinical implications for pathology workflows, and references to related procedural codes used when additional stains or specialized analyses are performed.
The publication explains typical clinical settings and service delivery for 88342, clarifies how this procedure fits into pathology diagnostic sequences, and outlines operational considerations affecting billing and documentation. It also highlights related services such as additional antibody stains and manual morphometric analysis to help readers understand code relationships and common billing scenarios. Data not available in the input where applicable will be clearly noted in the detailed sections.
Billing Code Overview
CPT code 88342 describes a pathology service in which a laboratory analyst performs an initial single antibody immunohistochemical stain on slide(s) prepared from a single patient specimen, commonly tumor tissue. A qualified provider, typically a pathologist, then reviews and interprets the stained slide(s) to render a pathologic diagnosis.
Service Type: Immunohistochemistry single antibody stain with pathologist interpretation
Typical Site of Service: Hospital pathology laboratory, independent or hospital-affiliated diagnostic laboratory, or outpatient pathology laboratory
Clinical & Coding Specifications
Clinical Context
A 62-year-old male undergoes a diagnostic core needle biopsy of a suspicious right breast mass identified on imaging. The surgical pathology laboratory receives formalin-fixed, paraffin-embedded tissue blocks and prepares routine hematoxylin and eosin (H&E) slides. Because morphology is indeterminate for receptor status and to distinguish invasive carcinoma from in situ disease, the laboratory technologist performs an initial single antibody immunohistochemical (IHC) stain on a slide from the biopsy specimen (for example, estrogen receptor or cytokeratin). A board-certified pathologist reviews the stained slide(s), interprets the staining pattern in the context of the H&E morphology, and issues a pathologic diagnosis and IHC interpretation in the final report.
Typical workflow steps:
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Specimen accessioning and gross description.
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Slide preparation from the patient's paraffin block and selection of target slide.
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Laboratory analyst/technologist performs a single antibody stain (
CPT 88342) on the slide. -
Qualified pathologist performs microscopic review of H&E and IHC-stained slides, documents findings, and signs out the report.
Typical site of service: Hospital-based surgical pathology laboratory or independent anatomic pathology reference laboratory.
Service type: Anatomic pathology procedure (single antibody immunohistochemistry with pathologist interpretation).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the pathologist's interpretive (professional) component separate from the technical staining performed by the laboratory. |
| TC | Technical component | Use when billing only the laboratory technical component (stain and slide preparation) separate from the pathologist interpretation.
| 59 | Distinct procedural service | Use when the IHC stain represents a distinct service from other procedures performed on the same day and documentation supports separate reporting.
| 76 | Repeat procedure by same provider | Use when the same single antibody stain is repeated by the performing laboratory because of technical failure or additional tissue requirement.
| 77 | Repeat procedure by another provider | Use when a different laboratory repeats the single antibody stain on the same patient specimen.
| 52 | Reduced services | Use when the IHC procedure is partially performed or limited compared with the full service (document reason for reduction).
| 53 | Discontinued procedure | Use when staining is initiated but discontinued for clinical or technical reasons and documentation supports reporting as discontinued.
| 90 | Reference (outside) laboratory | Use when the IHC stain was performed by an outside reference laboratory and only the ordering laboratory bills for interpretation or coordination.
| 91 | Repeat clinical diagnostic laboratory test | Use when a repeat single antibody stain is performed for verification or quality control purposes per laboratory policy.
| QW | CLIA-waived test | Generally not applicable to IHC; include only if regulatory status justifies modifier use (rare for this procedure).
| RT | Right side | Use when laterality is reportable and the specimen is from the right anatomical site (for example, right breast) and payer requires laterality reporting.
| LT | Left side | Use when laterality is reportable and the specimen is from the left anatomical site and payer requires laterality reporting.
| 22 | Increased procedural services | Use when the IHC procedure requires substantially greater work or resources than typical; documentation must support the circumstances.
| 52 | Reduced services | (Duplicate row avoided) See above.
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207ZP0102X | Anatomic Pathology & Clinical Pathology | Pathologists and laboratorians performing and interpreting IHC in surgical pathology. |
| 207ZP0101X | Cytopathology | Cytopathologists who may request or interpret IHC on cell block material.
| 207ZP0007X | Pathology | General pathology practice covering anatomic pathology IHC services.
| 207ZP0104X | Forensic Pathology | Forensic pathologists who may apply IHC in medicolegal tissue evaluations.
| 207ZP0105X | Hematology | Hematopathologists who use single antibody stains for hematolymphoid neoplasm characterization.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
C50.911 | Malignant neoplasm of unspecified site of right female breast | IHC stains are used to subtype breast neoplasms and determine receptor status for diagnosis and treatment planning. |
| C61 | Malignant neoplasm of prostate | IHC can assist in confirming prostatic origin and distinguishing primary prostate carcinoma from metastatic disease.
| D49.2 | Neoplasm of unspecified behavior of bone, soft tissue, and skin | Single antibody stains help classify soft tissue and skin neoplasms when morphology is indeterminate.
| C34.90 | Malignant neoplasm of unspecified part of unspecified bronchus or lung | IHC assists in differentiating lung primary tumors from metastatic disease and in histologic subtyping.
| D05.10 | Carcinoma in situ of unspecified breast | IHC may be used adjunctively to assess markers that inform risk stratification or management.
| C18.9 | Malignant neoplasm of colon, unspecified | IHC can help distinguish primary colorectal adenocarcinoma from metastasis and assess mismatch repair proteins when indicated.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
88341 | Each additional single antibody stain procedure | Billed when more than one distinct single antibody IHC stain is performed on the same specimen; follows CPT 88342 for the first stain. |
| 88360 | Manual morphometric analysis | Used when manual morphometric analysis is required in addition to IHC interpretation for quantitative assessment; may be billed separately when documented.