Prior authorization — routine thyroid tests covered when meeting criteria

Most routine thyroid laboratory tests are covered when ordered for indications and frequencies specified in the policy; the document does not list additional, separate prior authorization CPT/HCPCS requirements in the cited sections. When requesting authorization, use the exact procedure codes listed in the policy's coding section.

• TSH meets coverage criteria for specified indications with frequency limits (e.g., ≤1 test every 6 weeks for many indications; once every 3 months for IRT/ale mtuzumab and certain drugs).
• No separate PA-triggering CPTs are named in the indicated excerpts — confirm coding/authorization requirements with current payer systems prior to submission.

Testing requirements — start with TSH; use fT4 (or TT4 in pregnancy)

When screening or evaluating thyroid function, start with serum TSH as the first-line test; follow abnormal TSH with free T4 (fT4). In pregnancy, if trimester-specific fT4 reference ranges are unavailable, use total T4 (TT4) with pregnancy‑adjusted ranges or a free thyroxine index per specialty guidance.

• First-line screening: TSH measurement.
• Reflex/follow-up: fT4 after abnormal TSH; TT3/fT3 when TSH is low to confirm hyperthyroidism.
• Pregnancy: prefer trimester-specific fT4; if unavailable, use TT4 with pregnancy‑adjusted reference ranges or FT4 index.

Prior authorization requirements — not specified in excerpts

The provided excerpts do not specify additional prior authorization rules beyond the coverage criteria; they state most routine thyroid tests meet coverage when clinical indications and frequency criteria are satisfied.

• Policy indicates coverage is based on clinical indications and allowed frequencies rather than listing PA-only CPTs in these sections.
• Confirm any payer-specific PA processes or code-level requirements before submitting.

Procedure codes — use exact CPT/HCPCS codes from policy

When requesting authorizations or billing, include the exact CPT/HCPCS procedure codes listed in the policy's coding table. Use these codes to identify the specific assay or panel being ordered.

• Examples of listed codes: 80438, 80439, 83519, 83520, 84432, 84436, 84439, 84442, 84443, 84445, 84479, 84480, 84481, 84482, 86376, 86800.
• Include the appropriate code(s) on authorization requests to match the test(s) performed.

Procedure/coding — use listed CPTs; some tests (TBG/TRH/reverse T3) are non-covered

Order and code tests exactly as listed; several specific assays are identified as not meeting coverage criteria and will be denied if billed. Do not submit authorization requests for tests explicitly listed as non-covered.

• Tests listed in coding (e.g., 84442 TBG; 84482 reverse T3) are included for reference; however, TBG, TRH and reverse T3 are identified elsewhere as not meeting coverage criteria.
• Requests for non-covered tests should not be expected to meet medical necessity and may be denied.

Coding changes may affect authorization — confirm current code coverage

Coding changes and removals are documented in the revision history; providers should confirm current code coverage and payer acceptance before submitting authorization or billing to avoid denials related to obsolete codes.

• Revision history documents addition and later removal of certain CPTs (e.g., 84442 added then removed; codes 80438 & 80439 later marked as no longer covered).
• Verify the payer's active code list and prior authorization requirements at the time of service.

Step therapy — none described

No step therapy or medication-step requirements are described in the provided policy excerpts.

• Policy does not impose step therapy for ordering thyroid laboratory tests.
• Clinical evaluation should still follow guideline-based sequencing (TSH first, then reflex tests as indicated).

Stepwise testing — TSH first, confirm with fT4 before broader testing

Follow a stepwise testing approach: measure TSH first and confirm abnormal results with fT4 before ordering broader panels or imaging.

• Start with TSH for initial evaluation; confirm diagnosis with free T4.
• Reserve TT3/fT3 for low TSH to establish hyperthyroidism rather than ordering broad panels initially.

Cascading initial testing — TSH then reflex to fT4/±fT3

Use a cascading testing strategy: obtain TSH first and then reflex to fT4 (and fT3/TT3 if indicated) rather than ordering multiple thyroid assays up-front.

• If TSH above reference range → measure fT4 in same sample.
• If TSH below reference range → measure fT4 and fT3 (or TT3) in same sample.

Cascade testing approach — TSH first-line with reflex fT4/fT3 per criteria

The policy defines a cascade approach with TSH as first-line and reflex/follow-up fT4/fT3 testing per specified scenarios; order tests accordingly to align with coverage criteria.

• CC1–CC4 reorganized to emphasize TSH first-line and conditional follow-up testing.
• Reflex testing for IRT/ale mtuzumab and pregnancy-specific monitoring are described in criteria.

Documentation — record clinical indication and risk factors to support testing

Document the clinical indication and patient risk factors when ordering thyroid tests (e.g., signs/symptoms of hypo- or hyperthyroidism, pregnancy status, medication exposures, history of thyroid disease or nodules, IRT/HAART/BMT/HSCT, recurrent pregnancy loss) and include timing/frequency of prior tests to support medical necessity.

• Include signs/symptoms or specific risk factors that match policy criteria.
• When applicable, document prior test dates and the monitoring plan (e.g., dose changes and intended recheck interval).

Pregnancy testing documentation — indicate reason, reference ranges, and monitoring plan

When testing pregnant patients, document the indication (personal/family history of thyroid disease, type 1 diabetes, clinical suspicion, infertility, or recurrent pregnancy loss), use trimester‑specific reference ranges when available, and document the monitoring plan and TSH targets or dose adjustments for levothyroxine.

• Document pregnancy status and the specific reason for testing (risk factor or symptoms).
• Record trimester-specific reference ranges or the use of TT4/FT4 index if FT4 assay is unreliable in pregnancy; document planned monitoring intervals (e.g., every 4–6 weeks while adjusting therapy).

Document clinical indication and monitoring plan — specify recheck intervals

Document a monitoring plan when ordering tests for treatment monitoring (e.g., state that TSH will be rechecked every 6 weeks during dose changes for primary hypothyroidism or that fT4 will be rechecked every 6 weeks for secondary hypothyroidism while doses change).

• For primary hypothyroidism: document intent to recheck TSH every 6 weeks during dose titration and annually once stable.
• For secondary hypothyroidism: document plan to monitor fT4 every 6 weeks during dose changes and annually when stable.

Clinical indication documentation — tie orders to policy criteria

Document clinical indications consistent with the policy's clinical criteria when ordering tests (e.g., risk factors, symptoms, pregnancy status, monitoring after treatment) to support medical necessity.

• Tie orders to policy-listed indications (e.g., thyroid nodule, two or more pregnancy losses, IRT exposure).
• Include relevant clinical notes in the medical record or authorization request.

Cascading testing approach — avoid simultaneous broad panels

Begin with TSH for initial evaluation and cascade to fT4 (and fT3/TT3 if indicated) rather than ordering broad panels; this reduces risk of denials for non-guideline testing.

• ASCP and NICE recommend starting with TSH and only ordering follow-up tests based on TSH result.
• Avoid ordering multiple initial thyroid assays simultaneously without documented indication.

Denial risk — excluded tests (TBG, TRH, reverse T3, T3 uptake) will be denied

Do not order tests that the policy explicitly excludes. Testing for thyroxine‑binding globulin (TBG), thyrotropin‑releasing hormone (TRH), reverse T3, or T3 uptake DOES NOT MEET COVERAGE CRITERIA and requests will be denied.

• TBG is listed as excluded under any circumstances.
• Requests for TRH or TBG testing for evaluation of the cause of hypo- or hyperthyroidism will be denied.

Denial risk — non‑targeted routine screening may be denied

Ordering thyroid tests during a general exam or routine well visit without abnormal findings or targeted clinical indication is not covered and may be denied; routine TSH screening in asymptomatic adults is discouraged by guideline bodies.

• Do not perform non‑targeted TSH screening on asymptomatic adults during annual exams without documented risk factors or symptoms.
• Document specific clinical findings or risk that justify testing to avoid denial.

Government policy precedence — follow LCD/NCD/Medicaid when conflicting

If this policy conflicts with an applicable government policy (e.g., Medicare LCD/NCD or state Medicaid), the government policy takes precedence and will be used to determine coverage.

• Check applicable LCDs/NCDs or state Medicaid rules for members covered by those programs prior to requesting authorization.
• When in doubt, follow the government policy applicable to the member.

Excluded tests — TBG/TRH/reverse T3 classified as never covered

Requests for testing thyroxine‑binding globulin (TBG), thyrotropin‑releasing hormone (TRH), or reverse T3 will be denied; the revision history and exclusions explicitly state these tests DO NOT MEET COVERAGE CRITERIA.

• Policy revision history explicitly moved TBG/TRH/reverse T3 into the never-covered category (CC8/CC9).
• Do not submit authorization/billing requests for these assays expecting coverage.

Denied tests — TRH/TBG for etiologic evaluation will be denied

Testing for TRH or TBG to evaluate the cause of hyperthyroidism or hypothyroidism does not meet coverage criteria and may be denied if submitted for that purpose.

• Revision history explicitly states TRH/TBG testing for evaluation of cause of thyroid disease does not meet coverage criteria.
• Codes previously associated with TRH panels (80438, 80439) were removed from coverage per coding changes.