Ordering RecommendationRecommendations when to order or not order the test. May include related or preferred tests.
Not recommended for routine evaluation of thyroid disorders. Preferred test is Thyroxine, Free (Free FT4) (0070138).
MnemonicUnique test identifier.
FT4 ED-TMS
MethodologyProcess(es) used to perform the test.
Quantitative Equilibrium Dialysis/High Performance Liquid Chromatography-Tandem Mass Spectrometry
PerformedDays of the week the test is performed.
Sun, Tue, Thu
ReportedExpected turnaround time for a result, beginning when ARUP has received the specimen.
2-5 days
New York DOH Approval StatusIndicates test has been approved by the New York State Department of Health.
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect
Plain Red or Serum Separator Tube (SST).
Specimen Preparation
Separate from cells or gel ASAP or within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 0.3 mL)
Storage/Transport Temperature
Refrigerated.
Unacceptable Conditions
Plasma.
Remarks
Stability
After separation from cells: Ambient: 4 days; Refrigerated: 2 weeks; Frozen: 1 month
Reference IntervalNormal range/expected value(s) for a specific disease state. May also include abnormal ranges.
Effective May 16, 2011
Free Thyroxine ng/dL
Age
Female
Male
25-30 weeks gestation
0.5-3.3 ng/dL
0.5-3.3 ng/dL
31-36 weeks gestation
1.3-4.7 ng/dL
1.3-4.7 ng/dL
Birth to 1 week
2.2-5.3 ng/dL
2.2-5.3 ng/dL
2-3 weeks
0.9-4.0 ng/dL
0.9-4.0 ng/dL
1-5 months
1.1-2.2 ng/dL
1.1-2.2 ng/dL
6 months-6 years
1.4-2.7 ng/dL
1.4-2.7 ng/dL
7 years-17 years
1.1-2.0 ng/dL
1.1-2.0 ng/dL
18 years and older
1.1-2.4 ng/dL
1.1-2.4 ng/dL
Pregnancy, 1st Trimester
0.7-2.0 ng/dL
Pregnancy, 2nd Trimester
0.7-2.1 ng/dL
Pregnancy, 3rd Trimester
0.5-1.6 ng/dL
Interpretive DataBackground information for test. May include disease information, patient result explanation, recommendations, details of testing, associated diseases, explanation of possible patient results.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Compliance Category
Laboratory Developed Test (LDT)
NoteAdditional information related to the test.
Hotline History
N/A
CPT CodesThe American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* 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.
AliasesOther names that describe the test. Synonyms.
Direct Dialysis
FT4
T4, Free, Equilibrium Dialysis
Thyroxine, Free by Equilibrium Dialysis/HPLC-Tandem Mass Spectrometry
Chat
Feedback
