FREE THYROXINE INDEX (FTI), SERUM

Additional Codes

Software	Test Code
Label Text	FTIN
EPIC	LAB10245

Performing Laboratory

NorDx Laboratories

Useful For

Includes total T4 and T4 uptake

Method Name

Electrochemiluminescent Immunoassay (ECLIA)

Reference Values

T4 TOTAL

Up to 3 years: 6.8-13.5 ug/dL

3 to 10 years: 5.5-12.8 ug/dL

10 years and older: 5.3-12.3 ug/dL

T4 (THYROXINE), UPTAKE

0.8-1.3 TBI

FREE THYROXINE INDEX

4.4 -11.4 ug/dL

Days and Times Test Performed

Monday through Friday

Report Available

1 Day

Profile Information

Individual Test Description
FREE THYROXINE INDEX
THYROXINE (T4), TOTAL, SERUM
THYROXINE (T4), UPTAKE, SERUM

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
84436	Thyroxine, Total, Quantitative
84479	Thyroid Hormone (T3 or T4) Uptake or Thyroid Hormone Binding Ratio (THBR)

Performing Laboratory Location