Summary & Overview
CPT 88348: Diagnostic Electron Microscopy for Tissue Specimens
CPT code 88348 covers diagnostic electron microscopy using a conventional transmission electron microscope (CTEM) to examine specimens such as kidney biopsies, muscle tissue, and tumors. Electron microscopy provides ultrastructural detail essential for diagnosing certain renal, neuromuscular, and neoplastic conditions that are not resolvable by light microscopy alone. Nationally, this code represents a specialized pathology service concentrated in hospital and reference laboratories and informs coverage, utilization, and laboratory workflow discussions.
Key payers considered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical indications for ultrastructural examination, typical sites of service where 88348 is furnished, and common billing considerations tied to laboratory practice. The publication summarizes benchmark utilization patterns and payer coverage themes where available, describes policy and coding guidance relevant to electron microscopy services, and outlines how 88348 fits into the diagnostic pathway alongside other pathology modalities.
This summary is intended for clinical laboratory managers, health policy analysts, billing professionals, and payer policy teams seeking concise context on the clinical role and billing characteristics of CPT code 88348 at a national level. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 88348 describes the use of a diagnostic electron microscope (conventional transmission electron microscope, CTEM) by an analyst to evaluate patient specimens such as kidney biopsies, muscle samples, or tumor tissues. This service involves ultrastructural examination to identify cellular and subcellular pathology that cannot be resolved by light microscopy alone.
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Service type: Diagnostic electron microscopy (ultrastructural pathology analysis)
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Typical site of service: Hospital-based pathology laboratories, specialized reference laboratories, and academic medical center pathology departments
Clinical & Coding Specifications
Clinical Context
A 52-year-old patient undergoes a renal biopsy for evaluation of persistent proteinuria and declining renal function. Light microscopy and immunofluorescence are performed first; results are inconclusive for an ultrastructural process. A transmission electron microscopy study is requested on the same biopsy specimen to evaluate glomerular basement membrane changes, podocyte foot process effacement, or immune complex localization. The clinical workflow: the nephrology team obtains the biopsy in the interventional suite; the specimen is fixed and forwarded to the pathology laboratory. A histology technologist processes light and immunofluorescence slides; when electron microscopy is requested, a renal tissue fragment is specifically post-fixed and embedded for ultrathin sectioning. A pathologist or electron microscopy analyst performs 88348 to examine ultrastructural features, documents findings in the pathology report, and communicates results to the treating nephrologist for definitive diagnosis and management planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component of the electron microscopy when separate technical component is billed by another entity. |