Ordering RecommendationRecommendations when to order or not order the test. May include related or preferred tests.
Not the preferred initial thyroid disorder screening test. Order following an abnormal thyroid stimulating hormone (TSH) result to diagnose thyroid disease. Order in conjunction with Thyroid Stimulating Hormone (0070145) in cases of suspected secondary hypothyroidism.
MnemonicUnique test identifier.
FT4
MethodologyProcess(es) used to perform the test.
Quantitative Electrochemiluminescent Immunoassay
PerformedDays of the week the test is performed.
Sun-Sat
ReportedExpected turnaround time for a result, beginning when ARUP has received the specimen.
Within 24 hours
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
Serum separator tube or plasma separator tube. Also acceptable: Green (sodium or lithium heparin) or lavender (EDTA).
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
Refrigerated.
Unacceptable Conditions
Grossly hemolyzed specimens.
Remarks
Stability
After separation of cells: Ambient: 5 days; Refrigerated: 1 week; 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
0-3 days
0.7-2.7 ng/dL
4-30 days
0.8-3.1 ng/dL
1-23 months
0.5-2.3 ng/dL
2-6 years
0.9-1.8 ng/dL
7-11 years
0.9-1.7 ng/dL
12-19 years
0.9-1.6 ng/dL
20 years and older
0.8-1.7 ng/dL
Pregnancy, 1st Trimester
0.9-1.4 ng/dL
Pregnancy, 2nd Trimester
0.7-1.3 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.
Compliance Category
FDA
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.