Thyroid Panel (T4/T3U/T7)

Cleveland Heartlab T, Test

CPT Code: 84436 (x1), 84479 (x1)
Order Code: C1374
Includes: T3 Uptake, Thyroxine Total (T4 Total), Free T4 Index (T7)
ABN Requirement: No
Synonyms: Free T7; FTI; T3/T4; T3/T4/T7; T7; T7 Index; Thyroid Profile
Specimen: Serum
Volume:  1.0 mL
Minimum Volume:  0.5 mL
Container: Gel-barrier tube (SST, Tiger Top)



  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. Do not shake.
  3. Let tube stand in a vertical position to allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Transport: Store serum at 2-8°C after collection and ship the same day per packaging instructions included with the provided shipping box.


Ambient (15-25°C): 7 days
Refrigerated (2-8°C):
7 days
Frozen (-20°C):
28 days

Causes for Rejection: Specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits

Methodology: Immunoassay (IA)

Turn Around Time: 2-3 days

Reference Range:

T4 (Thyroxine), Total

Age Male (mcg/dL) Female (mcg/dL)
<1 month 4.5-17.2 4.5-17.2
1-23 month 5.9-13.9 5.9-13.9
2-12 years 5.7-11.6 5.7-11.6
13-20 years 5.1-10.3 5.3-11.7
>20 years 4.9-10.5 5.1-11.9


All Ages %
T3 Uptake 22-35


All Ages
Free T4 Index (T7) 1.4-3.8

Clinical Significance: For diagnosis of hypothyroidism and hyperthyroidism.

The CPT codes provided 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 payer being billed.