Summary & Overview
CPT 83045: Methemoglobin Assay, Whole Blood
CPT code 83045 denotes a laboratory assay for methemoglobin in whole blood, a diagnostic test used to identify methemoglobinemia caused by genetic variants or exposure to oxidizing drugs or chemicals. Nationally, accurate identification of methemoglobinemia is clinically important because it can lead to tissue hypoxia and requires specific management. This code is relevant across acute care, hospital laboratory, and emergency settings where rapid testing informs urgent treatment decisions.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical context, typical sites of service, and common billing considerations. The publication provides benchmarks where available, notes on payer coverage patterns, and relevant policy updates that affect laboratory reimbursement and documentation requirements. Clinical context clarifies when testing is indicated and how results influence patient management. Data not available in the input is noted when applicable.
Billing Code Overview
CPT code 83045 identifies a laboratory test used to determine the presence and concentration of methemoglobin in a whole blood specimen. Methemoglobin is an altered form of hemoglobin that can give blood a brownish color and impair oxygen delivery. This assay is used when methemoglobinemia is suspected due to genetic defects or exposure to certain drugs or chemicals.
Service Type
- Laboratory diagnostic test
Typical Site of Service
- Clinical laboratory (hospital laboratory or independent reference lab)
- Emergency department or inpatient setting when rapid identification is needed for acute presentations
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult presenting to the emergency department or inpatient unit with cyanosis, altered mental status, tachycardia, or chocolate-brown colored blood after reported exposure to oxidizing agents (for example, topical benzocaine during dental procedures, nitrites, dapsone, or industrial chemicals) or after ingestion of well-known methemoglobinemia-inducing medications. The clinician obtains a whole blood sample and orders a methemoglobin level to confirm the diagnosis and guide therapy (such as supplemental oxygen, intravenous methylene blue when indicated, and supportive care). The clinical workflow includes blood draw by phlebotomy or bedside nursing, prompt transport to the clinical laboratory, analysis by the lab analyst using co-oximetry or spectrophotometric methods to determine percent methemoglobin, documentation of results in the electronic medical record, and communication of critical values to the treating team for immediate management decisions.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the physician interpretation component, applicable when a pathologist or physician provides interpretive services separate from the laboratory technical work. |
59 |