E02 ICD-10-CM Code: Subclinical iodine-deficiency hypothyroidism
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
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
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
MappedHCC 44
RAF 0.0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for E02 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for E02 in this effective period.
Related Child Codes
ICD-10-CM does not list child codes under E02 for this display context.
Includes
OfficialICD-10-CM does not list Includes notes for E02 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for E02 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for E02 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for E02 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for E02 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is E02 an HCC code?
No. E02 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.
Work E02 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for E02
For E02to 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 E02 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
Get the V28 RAF + MEAT cheat sheet
One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.
Free PDF. No card. Unsubscribe anytime.
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 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.
This code does not map to any HCC under V24 or V28, providing no community risk adjustment impact. It maps to RxHCC 44 (Osteoporosis, Vertebral and Pathological Fractures). Accurate coding supports prescription drug plan risk adjustment and ensures appropriate clinical management of this mild but potentially progressive condition.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, 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.