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T4, (Thyroxine), Free

Test Code
FT4


Preferred Specimen
Serum, 0.1 mL minimum


Transport Container
SST tube


Transport Temperature
Specimen stable for 8 hours at room temp., 2 days refrigerated and >2 days frozen.


Reference Range
See report for normal ranges.


Clinical Significance
Free T4 levels correlate with T4 secretion and metabolism. In hypothyroidism and hyperthyroidism, FT4 levels parallel changes in total T4 levels.




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.