E06.9
BillableThyroiditis, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E06.9 an HCC code?
No. E06.9 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for E06.9
For E06.9to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E06.9 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E06.9 is the ICD-10-CM diagnosis code for thyroiditis, unspecified. This code describes inflammation of the thyroid gland when the specific type or cause is not documented or known. The thyroid is a gland in the neck that produces hormones affecting metabolism and body functions. E06.9 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering disorders of thyroid gland (e00-e07).
E06.9 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Maps to RxHCC 44 (Osteoporosis, Vertebral and Pathological Fractures) in the prescription drug model. This code does not map to CMS-HCC v28 or v24 models. Pursuing diagnostic specificity may reveal autoimmune or other conditions with different risk profiles. The RxHCC mapping captures basic thyroid medication costs.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E06.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the type of thyroiditis (such as Hashimoto's, postpartum, or acute) cannot be determined from the medical record; always query the provider for more specific documentation if available
- •Review the clinical notes carefully for any mention of symptoms, lab results, or triggers that might indicate a more specific thyroiditis subtype, as E06.9 is a less specific code that may affect reimbursement
Clinical Significance
Unspecified thyroiditis is used when thyroid inflammation is documented but the specific type (acute, subacute, autoimmune, drug-induced, or other chronic) has not been determined or documented by the provider. This code represents a diagnostic gap that should ideally be resolved through additional clinical workup including thyroid antibodies, inflammatory markers, and imaging. Specificity in thyroiditis classification directly impacts treatment selection.
Documentation Requirements
- ✓Document the clinical evidence of thyroiditis (thyroid tenderness, laboratory abnormalities, imaging findings) and the reason the specific type has not been established.
- ✓Include plans for further diagnostic evaluation.
- ✓Record current thyroid function status and any empiric treatment initiated.
Commonly Confused Codes
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