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Test Name

TSH with Reflex to Free T4

CPT Code(s)

84443

Includes

For patients 1 year of age or older, Free T4 will be performed at an additional charge (CPT code(s): 84439) when TSH result exceeds age/gender specific reference range.

Methodology

Immunoassay

Reference Range(s)

Premature Infants (28-36 Weeks)  
  1st Week of Life 0.20-27.90 mIU/L
Term Infants (>37 Weeks)  
  Serum or Cord Blood 1.00-39.00 mIU/L
  1-2 Days 3.20-34.60 mIU/L
  3-4 Days 0.70-15.40 mIU/L
  5 Days-4 Weeks 1.70-9.10 mIU/L
  1-11 Months 0.80-8.20 mIU/L
  1-19 Years 0.50-4.30 mIU/L
  ≥20 Years 0.40-4.50 mIU/L
Pregnancy  
  First Trimester 0.26-2.66 mIU/L
  Second Trimester 0.55-2.73 mIU/L
  Third Trimester 0.43-2.91 mIU/L
TSH levels decline rapidly during the first week of life in most children, but may remain transiently elevated in a few individuals despite normal free T4 levels. For proper interpretation of an abnormal TSH from a newborn thyroid screen, a Free T4 by Dialysis (test code 35167) or Total T4 (test code 867) should be considered.

Clinical Significance

For differential diagnosis of primary, secondary, and tertiary hypothyroidism. Also useful in screening for hyperthyroidism. This assay allows adjustment of exogenous thyroxine dosage in hypothyroid patients and in patients on suppressive thyroxine therapy for thyroid neoplasia.

Alternative Name(s)

Thyroid Stimulating Hormone with Reflex

To view specimen requirements and codes please Select a regional laboratory.

Not sure which laboratory serves your office? Call us 866-MYQUEST (866-697-8378)

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

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.

* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.

43562A
36127X
36127
36127
36127
36127
43562A
36127
36127
36127X
34023
36127
36127
36127
36127
36127
36127
36127
36127
36127
43562A
36127X
43562A
36127
36127X
36127X
34023
36127
7584
36127
TSH with Reflex to Free T4
36127