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Test Code T4F Thyroxine (T4), Free, Serum

Additional Codes

Software Test Code
Label Text                                              T4F                                                      
EPIC LAB127

Performing Laboratory

NorDx Laboratories

Useful For

Obtaining a more accurate assessment of thyroid status in patients with abnormal T4-binding protein levels including those who are pregnant or receiving steroid therapy

Method Name

Electrochemiluminescent Immunoassay (ECLIA)

Reference Values

0.93 - 1.7 ng/dL
T4 Free may be artificially elevated by heparin.

Days and Times Test Performed

Monday through Sunday

Report Available

1 Day

Specimen Type

Serum

Preferred Container

Serum Separator Tube (SST)

Preferred Volume

Serum: 1 mL (Serum Separator Tube (SST))

Minimum Volume

Serum: 0.5 mL (Serum Separator Tube (SST))

Specimen Collection and Handling

Spin specimen, separate from clot and send refrigerated.

Specimen Stability Information

Specimen Type: Serum

Frozen: 1 Month

Refrigerated: 7 Days

Must be spun/separated within: 2 Hours

Add On Capable

Yes

Advance Beneficiary Notice Requirements

This test, when ordered on Medicare patients, is subject to the National Coverage Determination (NCD) policies. Please verify that the diagnosis code (ICD code) you have chosen demonstrates medical necessity for the test as documented in the physician’s patient record. The CMS web site is available to assist you with this verification. A properly executed Advance Beneficiary Notice (ABN) must be submitted with the specimen if medical necessity is not demonstrated by the ICD code chosen.

CPT Code Information

CPT Code

CPT Description

CPT Disclaimer

84439 Thyroxine, Free, Quantitative  

Keywords

FREE T4 (THYROXINE)

NON-PROTEIN BOUND TETRAIODOTHYRONINE

T4 (THYROXINE) FREE

THYROXINE

THYROXINE (T4), TOTAL OR FREE

Performing Laboratory Location

NorDx Laboratories

LOINC Code Information

3024-7

Acceptable Alternative Container(s)

Plasma Separator Tube (PST)

Red Top Tube