What is ICD-10 code E03.0?

E03.0 is the ICD-10-CM diagnosis code for Congenital hypothyroidism with diffuse goiter. A condition present at birth where the thyroid doesn't produce enough hormones and is also enlarged (goiter), resulting from thyroid development problems. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E03.0 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E03.0 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. E03.0 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. E03.0 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.

What is the V28 vs V24 difference for E03.0?

E03.0 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 model rewards E03.0 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting E03.0?

Distinguish from E03.1 by confirming the presence of goiter on physical examination or imaging Document the etiology if known (dysgenesis, dyshormonogenesis, etc.) for complete coding

E03.0: Congenital hypothyroidism with diffuse

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupE03.0Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

E03.0

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

Congenital hypothyroidism with diffuse goiter

A condition present at birth where the thyroid doesn't produce enough hormones and is also enlarged (goiter), resulting from thyroid development problems.

Buddy Insight

Congenital hypothyroidism with diffuse goiter occurs when the thyroid gland is present but unable to produce adequate thyroid hormone, leading to compensatory enlargement.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 44

Thyroid and Parathyroid Disor...

RAF 0.0

Code Trumping

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Code Book Path

Official

E03Other hypothyroidism

E03.0Congenital hypothyroidism with diffuse goiter

Inclusion Terms

Official

Congenital parenchymatous goiter (nontoxic)
Congenital goiter (nontoxic) NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E03.0 in this effective period.

Related Child Codes

Official

E03.1Congenital hypothyroidism without goiter

E03.2Hypothyroidism due to medicaments and other exogenous substances

E03.3Postinfectious hypothyroidism

E03.4Atrophy of thyroid (acquired)

E03.5Myxedema coma

Includes

Official

ICD-10-CM does not list Includes notes for E03.0 in this effective period.

Excludes 1

Official

transitory congenital goiter with normal function (P72.0)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E03.0 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E03.0 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E03.0 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation should confirm congenital hypothyroidism with a diffuse goiter present since birth or early infancy.

Newborn screening results, confirmatory thyroid function tests (elevated thyroid-stimulating hormone, low free thyroxine), thyroid imaging or ultrasound findings, and the etiology if identified should be recorded.

Current levothyroxine dose, growth trajectory, and developmental milestones should be documented at follow-up visits.

MEAT Support

HCC Buddy guidance

Documentation should confirm congenital hypothyroidism with a diffuse goiter present since birth or early infancy.

Current levothyroxine dose, growth trajectory, and developmental milestones should be documented at follow-up visits.

Audit Caution

HCC Buddy guidance

Ensure the hypothyroidism is truly congenital (present from birth) and not acquired in childhood.

The presence of a goiter distinguishes this from agenesis or ectopic thyroid (E03.1).

Do not confuse with transient neonatal hypothyroidism, which resolves spontaneously.

Ensure ongoing levothyroxine treatment is documented at each visit to support the active diagnosis.

Common Mistakes

HCC Buddy guidance

E03.1 (Congenital hypothyroidism without goiter) is used when the thyroid is absent (agenesis) or ectopic without enlargement.

E00.1 (Congenital iodine-deficiency syndrome, myxedematous type) has a specific iodine-deficiency etiology.

E01.0 (Iodine-deficiency related diffuse goiter) is for acquired, not congenital, iodine-deficiency goiter.

E07.1 (Dyshormonogenetic goiter) may overlap etiologically.

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 E03.0 an HCC code?

No. E03.0 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 44, Thyroid and Parathyroid Disorders

0.000

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 E03.0

For E03.0to 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 E03.0 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

E03.0 is the ICD-10-CM diagnosis code for congenital hypothyroidism with diffuse goiter. A condition present at birth where the thyroid doesn't produce enough hormones and is also enlarged (goiter), resulting from thyroid development problems. E03.0 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).

E03.0 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). Despite the lack of community model RAF, this condition requires lifelong management and accurate coding supports prescription drug plan risk adjustment.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E03.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Distinguish from E03.1 by confirming the presence of goiter on physical examination or imaging
•Document the etiology if known (dysgenesis, dyshormonogenesis, etc.) for complete coding

Clinical Significance

Congenital hypothyroidism with diffuse goiter occurs when the thyroid gland is present but unable to produce adequate thyroid hormone, leading to compensatory enlargement. Common causes include dyshormonogenesis (enzyme defects in thyroid hormone synthesis) and transplacental passage of maternal goitrogens or antithyroid antibodies. Early identification through newborn screening and prompt levothyroxine replacement are critical to prevent irreversible intellectual disability and growth impairment.

Documentation Requirements

✓Documentation should confirm congenital hypothyroidism with a diffuse goiter present since birth or early infancy.
✓Newborn screening results, confirmatory thyroid function tests (elevated thyroid-stimulating hormone, low free thyroxine), thyroid imaging or ultrasound findings, and the etiology if identified should be recorded.
✓Current levothyroxine dose, growth trajectory, and developmental milestones should be documented at follow-up visits.

Excludes 1, Do NOT code together

transitory congenital goiter with normal function (P72.0)

Commonly Confused Codes

•E03.1 (Congenital hypothyroidism without goiter) is used when the thyroid is absent (agenesis) or ectopic without enlargement.
•E00.1 (Congenital iodine-deficiency syndrome, myxedematous type) has a specific iodine-deficiency etiology.
•E01.0 (Iodine-deficiency related diffuse goiter) is for acquired, not congenital, iodine-deficiency goiter.
•E07.1 (Dyshormonogenetic goiter) may overlap etiologically.