What is ICD-10 code E00.2?

E00.2 is the ICD-10-CM diagnosis code for Congenital iodine-deficiency syndrome, mixed type. A birth defect caused by severe iodine deficiency during pregnancy that results in multiple thyroid and developmental problems, including both goiter (enlarged thyroid) and intellectual disability. E00.2 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E00.2 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E00.2 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E00.2 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does E00.2 map to under V28?

E00.2 does not map to a CMS-HCC V28 payment category. Check the current CMS-HCC V28 model file for payment year 2026 rather than an older V24 tip sheet.

What does E00.2 pay in RAF?

E00.2 has no separately stated V28 community RAF weight. If it is not a V28 payment HCC, it adds nothing to a community RAF score.

What is the V28 vs V24 difference for E00.2?

E00.2 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither community model rewards E00.2 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's V28/V24 community RAF score in either version. It does, however, map under the Part D RxHCC model (Thyroid and Parathyroid Disorders), which affects the ESRD and/or Part D (RxHCC) risk scores. Coders should check whether provider documentation supports a more specific child code that does map to a community payment HCC.

What documentation supports E00.2?

This code indicates congenital cretinism with mixed manifestations; document whether goiter is present and severity of developmental delays Verify if this is truly congenital (present at birth) versus acquired iodine deficiency later in life E00.2 is not a CMS-HCC payment code, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

2026 ICD-10-CM E00.2: Congenital iodine-deficiency syndrome

E00.2 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC Buddy coding tools

ICD-10-CM Code View

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Code lookupE00.2Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Disorders of thyroid gland (E00-E07)

E00.2

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Congenital iodine-deficiency syndrome, mixed type

A birth defect caused by severe iodine deficiency during pregnancy that results in multiple thyroid and developmental problems, including both goiter (enlarged thyroid) and intellectual disability.

Buddy Insight

Congenital iodine-deficiency syndrome, mixed type, represents the combination of both neurological and myxedematous features resulting from severe prenatal iodine deficiency.

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

Mapped

HCC 44

Thyroid and Parathyroid Disor...

RAF 0.070

Code Book Path

Official

E00Congenital iodine-deficiency syndrome

E00.2Congenital iodine-deficiency syndrome, mixed type

Inclusion Terms

Official

Endemic cretinism, mixed type

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E00.2 in this effective period.

Related Child Codes

Official

E00.0Congenital iodine-deficiency syndrome, neurological type

E00.1Congenital iodine-deficiency syndrome, myxedematous type

E00.9Congenital iodine-deficiency syndrome, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for E00.2 in this effective period.

Excludes 1

Official

subclinical iodine-deficiency hypothyroidism (E02)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E00.2 in this effective period.

Use Additional

Official

code (F70-F79) to identify associated intellectual disabilities.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E00.2 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must clearly describe features of both neurological damage (intellectual disability, spasticity, hearing loss) and myxedematous hypothyroidism (growth failure, myxedema, delayed skeletal maturation) attributed to iodine deficiency.

Thyroid function tests, developmental assessments, and history of iodine-deficient environment should be recorded.

Current treatment including thyroid replacement and rehabilitation services should be documented.

MEAT Support

HCC Buddy guidance

Thyroid function tests, developmental assessments, and history of iodine-deficient environment should be recorded.

Current treatment including thyroid replacement and rehabilitation services should be documented.

Audit Caution

HCC Buddy guidance

Ensure documentation supports both neurological AND myxedematous components to justify the mixed type rather than defaulting to this code when the specific type is unclear.

If only one component is documented, assign the specific type (E00.0 or E00.1) rather than assuming mixed.

This condition is extremely rare in developed nations.

Additional codes for specific manifestations may be assigned.

Common Mistakes

HCC Buddy guidance

E00.0 (Neurological type) is used when neurological features predominate without significant hypothyroid manifestations.

E00.1 (Myxedematous type) is used when hypothyroid features predominate.

E00.9 (Unspecified) should not be used when the mixed presentation is documented.

E03.0-E03.1 (Congenital hypothyroidism) should not be used when iodine deficiency is the confirmed etiology.

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 E00.2 an HCC code?

E00.2 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Thyroid and Parathyroid Disorders under the Part D RxHCC model.

Code: E00.2
Description: Congenital iodine-deficiency syndrome, mixed type
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

RxHCCHCC 44, Thyroid and Parathyroid Disorders

0.070

Each model's RAF is its CMS base weight for that model's standard population, so 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 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 E00.2 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E00.2

For E00.2 to 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 E00.2 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E00.2 is the ICD-10-CM diagnosis code for congenital iodine-deficiency syndrome, mixed type. A birth defect caused by severe iodine deficiency during pregnancy that results in multiple thyroid and developmental problems, including both goiter (enlarged thyroid) and intellectual disability. E00.2 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).

E00.2 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 a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing E00.2 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E00.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This code indicates congenital cretinism with mixed manifestations; document whether goiter is present and severity of developmental delays
•Verify if this is truly congenital (present at birth) versus acquired iodine deficiency later in life

Clinical Significance

Congenital iodine-deficiency syndrome, mixed type, represents the combination of both neurological and myxedematous features resulting from severe prenatal iodine deficiency. Patients exhibit both the neurological damage (intellectual disability, motor deficits) and the hypothyroid manifestations (growth retardation, myxedema) seen in the individual types. This mixed presentation reflects the dual impact of iodine deficiency on both brain development and thyroid function.

Documentation Requirements

✓Documentation must clearly describe features of both neurological damage (intellectual disability, spasticity, hearing loss) and myxedematous hypothyroidism (growth failure, myxedema, delayed skeletal maturation) attributed to iodine deficiency.
✓Thyroid function tests, developmental assessments, and history of iodine-deficient environment should be recorded.
✓Current treatment including thyroid replacement and rehabilitation services should be documented.

Commonly Confused Codes

•E00.0 (Neurological type) is used when neurological features predominate without significant hypothyroid manifestations.
•E00.1 (Myxedematous type) is used when hypothyroid features predominate.
•E00.9 (Unspecified) should not be used when the mixed presentation is documented.
•E03.0-E03.1 (Congenital hypothyroidism) should not be used when iodine deficiency is the confirmed etiology.