CurrentArizona Complete HealthPolicy CP.MP.154

Thyroid Hormones and Insulin Testing in Pediatrics

Defines medical necessity and coding guidance for thyroid (TSH, T3, T4) and insulin testing in children age 1–18, focusing on routine testing in healthy or obese-but-otherwise-healthy pediatric patients for plans affiliated with Centene Corporation/Arizona Complete Health.

Policy Summary

PayerArizona Complete Health

PolicyThyroid Hormones and Insulin Testing in Pediatrics

Policy CodePolicy CP.MP.154

Change TypeNo material change

Effective Date

Next Review Date

Key ActionDo not order routine thyroid or insulin testing for otherwise healthy pediatric patients age 1–18; these tests are not medically necessary and claims may be denied.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

1–18age range addressed

Not medically necessaryroutine thyroid testing

Not medically necessaryroutine insulin testing

9CPT codes listed

10+ICD-10 codes listed

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Coverage Criteria — Thyroid and Insulin Testing (Pediatrics)

Not medically necessary — routine testing

Routine thyroid testing in healthy children: Routine thyroid hormone testing in healthy, including obese but otherwise healthy, children (age ≥ 1 and ≤ 18) is not medically necessary because these tests have not been demonstrated to have a clear clinical benefit.

Applies to testing billed with CPT/ICD combinations listed in coding tables.

Routine insulin testing in healthy children: Routine insulin testing in healthy, including obese but otherwise healthy, children (age ≥ 1 and ≤ 18) is not medically necessary because these tests have not been demonstrated to have a clear clinical benefit.

Insulin measurement lacks standardized assays and clinically useful thresholds in youth; considered a research tool.

The policy does not list specific clinical exceptions within Criteria I or II. However, professional guideline recommendations are acknowledged: endocrine evaluation may be appropriate when growth parameters are abnormal. Specifically, the Endocrine Society and the American Academy of Pediatrics recommend targeted endocrine assessment when a child’s stature and/or height velocity are attenuated relative to their genetic/familial potential and pubertal stage. In those situations, focused testing guided by clinical findings — rather than routine population screening — is the advised approach.

Providers should therefore consider endocrine referral or targeted laboratory assessment only when clinical indicators of endocrine disease are present (for example, abnormal growth pattern or delayed/precocious pubertal development). Routine, untargeted testing in asymptomatic children is not supported by guideline recommendations and is not covered by this policy.

Routine thyroid hormone testing and routine insulin testing in otherwise healthy pediatric patients age 1–18 years, including those who are obese but otherwise healthy, are not medically necessary because these tests have not been demonstrated to provide clear clinical benefit. The policy applies when the listed CPT codes are billed with the corresponding ICD-10-CM codes in the coding tables.

The coding tables enumerate specific procedure codes for thyroid and insulin assays (see Table 1) and diagnosis codes for well child/obesity encounters (see Table 2). Claims for the CPT/ICD-10-CM pairings shown may be denied as not medically necessary; inclusion of codes in the tables is informational and does not alone guarantee coverage.

Coding — CPT and ICD-10-CM Guidance

CPT Codes not medically necessary when billed with corresponding ICD-10-CMCPTNot Covered

83525	Insulin; total.
83527	Insulin; free.
84436	Thyroxine; total.
84439	Thyroxine; free.
84443	Thyroid stimulating hormone (TSH).
84479	Thyroid hormone (T3 or T4) uptake or thyroid hormone binding ratio (THBR).
84480	Triiodothyronine T3; total (TT-3).
84481	Triiodothyronine T3; free.
84482	Triiodothyronine T3; reverse

BMI obesity definition

DefinitionObesity in children is defined as an age- and sex-specific body mass index (BMI) at or above the 95th percentile plotted on CDC growth charts.

Measurement methodBMI percentile should be plotted on standard growth charts (e.g., CDC) to determine the percentile for age and sex.

Screening recommendationBMI measurement is the recommended screening test for obesity in pediatric patients.

Provider Actions, Billing Rules, and Denial Risk

Denial Risk

Not medically necessary code pairing

Not medically necessary code pairing — The CPT codes listed in Table 1 when billed with the corresponding ICD-10-CM diagnosis codes in Table 2 are considered not medically necessary.

Billing Rule

Provider coding reminder

Provider-focused reminder — Providers should review coding guidance prior to claim submission and ensure tests are billed with accurate diagnosis codes reflecting medical necessity.

Background — Clinical Context

Thyroid hormones regulate numerous metabolic processes via the hypothalamic–pituitary–thyroid axis. T4 (thyroxine) is the major secreted hormone of the thyroid and is converted peripherally to T3 (triiodothyronine); secretion of T4 is regulated by pituitary TSH. Disruption of the feedback loop can lead to hypo- or hyperthyroid states, which are diagnosed and managed based on clinical assessment combined with targeted hormone quantification.

In pediatrics, however, interpretation of thyroid and insulin laboratory values is complicated by associations with obesity and by assay limitations. TSH and total T4 may be elevated in children who are overweight or obese without clear evidence that these findings denote primary thyroid disease. Fasting insulin concentrations have substantial overlap between insulin-resistant and insulin-sensitive youths, lack standardized assays and reproducible thresholds, and therefore are of limited clinical utility for routine evaluation of obesity; measurement is considered primarily a research tool.

Definitions and Test Limitations

Thyroxine (T4) — key points

Primary hormoneThyroxine (T4) is the major secretory hormone of the thyroid and is converted to triiodothyronine (T3).

RegulationSecretion of T4 is regulated by thyroid stimulating hormone (TSH) produced by the pituitary, forming a feedback loop via the hypothalamic‑pituitary‑thyroid axis.

Clinical assessmentAssessment of thyroid function can be achieved through quantification of thyroid hormone levels (TSH, T4, T3).

Fasting insulin concentration limitations

Assay and threshold limitationsFasting insulin concentrations lack standardized assays and have poor reproducibility, limiting clinical reliability.

Overlap between groupsThere is considerable overlap in fasting insulin values between insulin‑resistant and insulin‑sensitive youths, so no clear numeric threshold distinguishes normal from abnormal insulin sensitivity.