Need help choosing the right code?
Ask CasePilot about procedures, modifiers, bundling, and coding guidance.
Try CasePilot© Copyright 2026 American Medical Association. All rights reserved.
The CPT® Code 84482 refers to the laboratory test for measuring reverse triiodothyronine (rT3) levels in a blood sample. Triiodothyronine, commonly known as T3, is a crucial hormone produced by the thyroid gland that plays a significant role in regulating various metabolic processes within the body, including body temperature, growth, and heart rate. T3 exists in two forms: the majority, approximately 95%, is bound to proteins in the bloodstream and is considered inactive, while the remaining 5% is free and biologically active. The measurement of T3 levels is essential for assessing thyroid function, diagnosing conditions such as hyperthyroidism, and monitoring patients with existing thyroid disorders. In the context of this test, reverse T3 is an inactive form of T3 that may be produced when the thyroid does not generate sufficient amounts of active T3 or when T4, another thyroid hormone, is not adequately converted into T3. The presence of elevated levels of reverse T3 can indicate potential thyroid dysfunction. The testing for reverse T3 is performed using radioimmunoassay, a sensitive laboratory technique that allows for the precise quantification of hormone levels in the blood. This test is particularly valuable in the comprehensive evaluation of thyroid health and function.
© Copyright 2026 Coding Ahead. All rights reserved.
The CPT® Code 84482 is indicated for use in various clinical scenarios related to thyroid function and disorders. The following conditions may warrant the measurement of reverse triiodothyronine (rT3):
The procedure for obtaining a reverse T3 measurement involves several key steps, which are outlined below:
After the procedure, the patient may resume normal activities immediately, as there are typically no significant side effects associated with blood sample collection. The results of the reverse T3 test are usually available within a few days, and the healthcare provider will discuss the findings with the patient. If elevated levels of reverse T3 are detected, further evaluation and management of the underlying thyroid condition may be necessary. It is important for patients to follow up with their healthcare provider to understand the implications of their test results and any potential next steps in their care.
| Short Descr | T3 REVERSE | Medium Descr | TRIIODOTHYRONINE T3 REVERSE | Long Descr | Triiodothyronine T3; reverse | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Conditionally packaged laboratory tests | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T1H - Lab tests - other (non-Medicare fee schedule) | MUE | 1 | CCS Clinical Classification | 233 - Laboratory - Chemistry and Hematology |
| 90 | Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number. | 77 | Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | GW | Service not related to the hospice patient's terminal condition | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 91 | Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient. | AY | Item or service furnished to an esrd patient that is not for the treatment of esrd | GA | Waiver of liability statement issued as required by payer policy, individual case | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | GY | Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit | GZ | Item or service expected to be denied as not reasonable and necessary | Q1 | Routine clinical service provided in a clinical research study that is in an approved clinical research study |
|
Date
|
Action
|
Notes
|
|---|---|---|
| 1993-01-01 | Added | First appearance in code book in 1993. |
Get instant expert-level medical coding assistance.