Overview
CPT® Code 84482 is used to report laboratory measurement of reverse triiodothyronine (rT3) in a patient’s serum or plasma. Reverse T3 is an inactive form of the thyroid hormone T3 and provides insight into thyroid function, metabolism, and certain non-thyroidal illnesses. Testing rT3 helps clinicians assess thyroid disorders, metabolic conditions, and hormone imbalances.
This code represents the laboratory assay itself. Interpretation, patient counseling, or clinical recommendations are not included and should be documented and billed separately if provided.
Key Facts About CPT® 84482
- Service type: Clinical laboratory test
- Provider type: Physicians, laboratories, and qualified healthcare professionals
- Medical services included: Quantitative measurement of reverse T3
- Specimen type: Serum or plasma
- Common clinical indications:
- Evaluation of thyroid function and metabolism
- Assessment of non-thyroidal illness syndrome (“euthyroid sick syndrome”)
- Monitoring treatment in hypothyroid or hyperthyroid patients
- Investigating unexplained fatigue, weight changes, or hormone imbalances
- Part of comprehensive thyroid panels
When to Use CPT® 84482
CPT 84482 is appropriate when:
- A serum or plasma sample is collected for rT3 testing
- Testing is medically necessary for diagnosis, monitoring, or treatment planning
- Results will directly influence clinical management
Examples:
- Monitoring thyroid hormone balance in patients on T4 therapy
- Evaluating rT3 in patients with suspected metabolic or systemic illness
- Investigating persistent fatigue with normal TSH and free T4 levels
Documentation Requirements
To properly support CPT 84482 billing, documentation should include:
- Patient identifiers and date of specimen collection
- Sample type (serum or plasma)
- Medical indication for testing
- Methodology used (immunoassay, chemiluminescence, or other validated methods)
- Test results and any follow-up recommendations
Accurate documentation ensures compliance, proper reimbursement, and integration into the patient’s longitudinal health record.
Reimbursement and Coding Considerations
- Covered by most commercial insurers, Medicare, and Medicaid when medically necessary
- Interpretation and clinical counseling are billed separately if provided
- Modifier usage may be required when multiple tests are performed on the same specimen
- Verify payer-specific rules for lab panels and bundling
How OptiMantra Supports Reverse T3 Testing
OptiMantra’s integrated EMR and practice management system simplifies lab workflow and documentation for CPT 84482.
With OptiMantra, providers can:
- Automatically link rT3 lab orders to the patient’s chart for longitudinal tracking
- Track hormone trends over time for informed clinical decisions
- Document medical indications and follow-up plans directly in the EMR
- Generate audit-ready, compliant billing codes for lab testing
- Integrate rT3 results with broader thyroid or endocrine care plans
By centralizing lab ordering, tracking, and documentation, OptiMantra ensures accurate records, streamlined workflows, and proper reimbursement for thyroid testing.
Try OptiMantra for free here!
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