Summary & Overview
CPT 82374: Serum Carbon Dioxide (Total CO2) Measurement
CPT code 82374 denotes a laboratory measurement of carbon dioxide, primarily in serum, representing total CO2 largely present as bicarbonate with some carbonic acid. This common serum chemistry test is a core component of metabolic panels and acid-base assessment and is widely used across inpatient and outpatient settings. Nationally, accurate coding and appropriate coverage of 82374 affect clinical decision-making, quality reporting, and laboratory billing workflows.
Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The discussion covers typical coverage considerations, billing practices, and where 82374 fits within standard laboratory testing panels.
Readers will find practical benchmarks and context for 82374, including typical sites of service and the clinical rationale for ordering the test. The publication outlines billing and policy considerations relevant to laboratories and clinicians, summarizes payer coverage patterns where available, and highlights areas where coding clarity can influence claims processing. Data not available in the input is noted where applicable, and the content is intended for a national audience seeking concise guidance on the use and billing of CPT code 82374.
Billing Code Overview
CPT code 82374 measures carbon dioxide (CO2) primarily in serum, reflecting the bicarbonate and carbonic acid content of blood. This laboratory chemistry test quantifies total CO2, which is used to assess acid-base balance and metabolic status.
Service Type: Clinical laboratory test — serum chemistry
Typical Site of Service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient presents to an outpatient laboratory after a primary care visit for evaluation of generalized weakness and mild dyspnea. The clinician orders basic metabolic testing including serum electrolyte panel and a carbon dioxide (bicarbonate) measurement to assess acid-base status and possible metabolic derangement. Venous blood is drawn in the clinic’s phlebotomy area and sent to the hospital laboratory. The laboratory analyst performs the assay quantifying total carbon dioxide in serum, which reflects bicarbonate concentration and helps guide diagnosis of metabolic acidosis, metabolic alkalosis, or evaluation of electrolyte disturbances. Results are reported to the ordering provider electronically, who integrates the value with sodium, potassium, chloride, creatinine, and clinical findings to determine further management.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the laboratory professional interpretation component, if applicable in a split billing arrangement. |
91 | Repeat clinical diagnostic laboratory test | Use when the carbon dioxide test is repeated on the same day to obtain serial values. |