Ordering Recommendation

Use to assess thyroid function or identify risk in individuals with palpable thyroid nodules. Test includes reflex to free thyroxine for thyroid stimulating hormone results outside the reference range.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube or plasma separator tube. Also acceptable: Lavender (EDTA) or green (sodium or lithium heparin).

Specimen Preparation

Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP standard transport tube. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Grossly hemolyzed specimens.


After separation of cells: Ambient: 5 days; Refrigerated: 1 week; Frozen: 1 month


Quantitative Electrochemiluminescent Immunoassay (ECLIA)




Within 24 hours

Reference Interval

Effective February 22, 2022

0-3 days 5.17-14.60 mU/L 5.17-14.60 mU/L
4-30 days 0.43-16.10 mU/L 0.43-16.10 mU/L
1-24 months 0.62-8.05 mU/L 0.62-8.05 mU/L
2-6 years 0.54-4.53 mU/L 0.54-4.53 mU/L
7-11 years 0.66-4.14 mU/L 0.66-4.14 mU/L
12-19 years 0.53-3.59 mU/L 0.53-3.59 mU/L
20 years and older 0.27-4.20 mU/L 0.27-4.20 mU/L
1st trimester (10-13 weeks gestation) 0.03-3.40 mU/L
2nd trimester (14-20 weeks gestation) 0.19-4.06 mU/L

Interpretive Data

Compliance Category



If the Thyroid Stimulating Hormone is outside the reference interval, then Thyroxine, Free (Free T4) testing will be added. Additional charges apply.

Hotline History


CPT Codes

84443; if reflexed, add 84439


Component Test Code* Component Chart Name LOINC
2006109 Thyroid Stim. Hormone w/Rflx to Free T4 3016-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Free T4
  • free thyroxine
  • Thyrotropin
  • TSH
Thyroid Stimulating Hormone with Reflex to Free Thyroxine