E02 ICD-10-CM Code: Subclinical iodine-deficiency hypothyroidism
E02 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools
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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Disorders of thyroid gland (E00-E07)
E02
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceSubclinical iodine-deficiency hypothyroidism
A mild form of low thyroid function caused by iodine deficiency where thyroid hormone levels are slightly low but the patient may have minimal or no symptoms.
Buddy Insight
Subclinical iodine-deficiency hypothyroidism represents a mild form of thyroid underfunction caused by inadequate iodine intake, characterized by elevated thyroid-stimulating hormone with normal free thyroxine levels.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
MappedHCC 44
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for E02. Check the code and parent instructions in the Code Book.
Excludes 2
OfficialNo Excludes 2 notes are included in this display for E02. Check the code and parent instructions in the Code Book.
Related Codes
No related codes are included in this display for E02. Check the Code Book for the complete code path.
Includes
OfficialNo Includes notes are included in this display for E02. Check the code and parent instructions in the Code Book.
Excludes 1
Official- transitory endocrine and metabolic disorders specific to newborn (P70-P74)Inherited from E00-E89
Code First
OfficialNo Code First sequencing instructions are included in this display for E02. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for E02. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for E02. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is E02 an HCC code?
E02 has no mapping under the current CMS-HCC V28 community payment model. E02 has a separate mapping under the Part D RxHCC model (HCC 44 (Thyroid Disorders)); the applicable result needs member context.
- Code
- E02
- Description
- Subclinical iodine-deficiency hypothyroidism
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work E02 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for E02
For E02, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
E02 is the ICD-10-CM diagnosis code for subclinical iodine-deficiency hypothyroidism. A mild form of low thyroid function caused by iodine deficiency where thyroid hormone levels are slightly low but the patient may have minimal or no symptoms. E02 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).
E02 has no mapping under the current CMS-HCC V28 community payment model. E02 has a separate mapping under the Part D RxHCC model (HCC 44 (Thyroid Disorders)); the applicable result needs member context. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.
Verify TSH and free T4 levels are in the subclinical range (elevated TSH with normal T4) to confirm this diagnosis.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for E02 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify TSH and free T4 levels are in the subclinical range (elevated TSH with normal T4) to confirm this diagnosis
- •Document whether the patient is symptomatic or asymptomatic, as this affects treatment decisions
Clinical Significance
Subclinical iodine-deficiency hypothyroidism represents a mild form of thyroid underfunction caused by inadequate iodine intake, characterized by elevated thyroid-stimulating hormone with normal free thyroxine levels. While patients are typically asymptomatic, the condition may progress to overt hypothyroidism if iodine deficiency persists. It is most relevant in populations without access to iodized salt and is distinguished from subclinical hypothyroidism of other etiologies.
Documentation Requirements
- ✓Documentation should include thyroid function tests showing elevated thyroid-stimulating hormone with normal free thyroxine levels, evidence or history of iodine deficiency, and clinical assessment for hypothyroid symptoms.
- ✓The provider must establish iodine deficiency as the etiology rather than autoimmune thyroiditis or other causes.
- ✓Treatment decisions (observation versus iodine supplementation versus levothyroxine) should be documented.
Commonly Confused Codes
- •E03.9 (Hypothyroidism, unspecified) captures overt or unspecified hypothyroidism without iodine-deficiency etiology.
- •E03.8 (Other specified hypothyroidism) captures specified non-iodine-deficiency hypothyroidism.
- •E01.0-E01.2 capture iodine-deficiency goiter, which may or may not coexist with hypothyroidism.
- •R94.6 (Abnormal results of thyroid function studies) is a findings code, not a diagnosis.