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The CPT® Code 84481 refers to the laboratory test for free triiodothyronine (T3), a crucial hormone produced by the thyroid gland. This test specifically measures the levels of free T3 in the blood, which is the active form of the hormone that plays a significant role in regulating various metabolic processes within the body, including body temperature, growth, and heart rate. T3 is primarily derived from the conversion of thyroxine (T4) and is predominantly found in two forms in the bloodstream: approximately 95% of T3 is bound to proteins, rendering it inactive, while the remaining 5% exists as free T3, which is biologically active and can exert its effects on target tissues. The measurement of free T3 is essential for assessing thyroid function, particularly in diagnosing conditions such as hyperthyroidism, where the thyroid gland is overactive. Additionally, this test is instrumental in monitoring patients who have been diagnosed with thyroid disorders, providing valuable insights into their treatment efficacy and overall thyroid health. The testing process for free T3 involves the use of electrochemiluminescent immunoassay, a sensitive and specific method that allows for accurate quantification of the hormone in the blood. This test is distinct from the total T3 test (CPT® Code 84480), which measures both bound and free T3, and from the reverse T3 test (CPT® Code 84482), which evaluates an inactive form of T3 that may indicate thyroid dysfunction when present in elevated levels.
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The free triiodothyronine (T3) test, represented by CPT® Code 84481, is indicated for several clinical scenarios related to thyroid function. The following conditions and symptoms may warrant the performance of this test:
The procedure for conducting the free T3 test involves several key steps to ensure accurate measurement of the hormone levels in the blood. The following procedural steps are typically followed:
After the free T3 test is performed, there are generally no specific post-procedure care requirements for the patient. However, patients may be advised to resume their normal activities immediately following the blood draw. It is important for healthcare providers to discuss the test results with the patient once they are available, as this will guide further management and treatment decisions related to thyroid health. Additionally, if the test results indicate abnormal levels of free T3, further diagnostic testing or interventions may be necessary to address any underlying thyroid conditions.
| Short Descr | FREE ASSAY (FT-3) | Medium Descr | ASSAY OF TRIIODOTHYRONINE T3 FREE | Long Descr | Triiodothyronine T3; free | 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. | Q4 | Service for ordering/referring physician qualifies as a service exemption | 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. | GA | Waiver of liability statement issued as required by payer policy, individual case | GW | Service not related to the hospice patient's terminal condition | 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 | 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. | Q1 | Routine clinical service provided in a clinical research study that is in an approved clinical research study | GZ | Item or service expected to be denied as not reasonable and necessary | Q5 | Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | 51 | Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d). | 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. | 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. | 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system. | CG | Policy criteria applied | GC | This service has been performed in part by a resident under the direction of a teaching physician | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | KX | Requirements specified in the medical policy have been met | PD | Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days | QJ | Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b) | QW | Clia waived test | RT | Right side (used to identify procedures performed on the right side of the body) | SA | Nurse practitioner rendering service in collaboration with a physician | XE | Separate encounter, a service that is distinct because it occurred during a separate encounter | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
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| 2013-01-01 | Changed | Medium Descriptor changed. |
| Pre-1990 | Added | Code added. |
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