2026 ICD-10-CM Diagnosis Code E00.9Congenital iodine-deficiency syndrome, unspecified

ICD-10-CM Codes›E00–E89›E00-E07›E00

ICD-10-CM E00.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E00.9 is a billable ICD-10-CM diagnosis code for congenital iodine-deficiency syndrome, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. Coders also document this condition as congenital hypothyroidism due to iodine deficiency. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

Code Identity

ICD-10-CM Code
E00.9
Billable Status
Yes — Valid for Submission
Code Describes
Congenital iodine-deficiency syndrome, unspecified
Short Description
Congenital iodine-deficiency syndrome, unspecified
Same as the full description in the CMS dataset.
Parent Code
E00
Congenital iodine-deficiency syndrome

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE00-E07Disorders of thyroid gland
CategoryE00Congenital iodine-deficiency syndrome
This CodeE00.9Congenital iodine-deficiency syndrome, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital hypothyroidism due to iodine deficiency
  • Congenital iodine deficiency syndrome
  • Endemic cretinism
  • Hypothyroidism due to defect in thyroid hormone synthesis
  • Primary hypothyroidism
  • Sporadic cretinism

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Congenital iodine-deficiency hypothyroidism NOS
  • Endemic cretinism NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Cretin, cretinism(congenital) (endemic) (nongoitrous) (sporadic)
    • Myopathy
      • in (due to)
        • cretinism
    • Syndrome
      • iodine-deficiency, congenital

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END001
Thyroid disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Iatrogenic Primary Hypothyroidism

    primary hypothyroidism due to medical or surgical treatment.

  • Primary Hypothyroidism

    abnormally low levels of thyroid hormones due to a disorder originating within the thyroid gland.

  • Transient Primary Hypothyroidism

    primary hypothyroidism that resolves spontaneously.

  • Endemic Cretinism

    severely reduced physical and mental growth associated with pyramidal and extrapyramidal signs and symptoms, due to dietary iodine deficiency.

Patient EducationClinical

Thyroid Diseases

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E00.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
243 Congenital hypothyroidsm
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E00.9Overview

Is E00.9 (Congenital iodine-deficiency syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report congenital iodine-deficiency syndrome, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E00.9 group to?

When congenital iodine-deficiency syndrome, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E00.9?

Under the General Equivalence Mappings, congenital iodine-deficiency syndrome, unspecified converts to ICD-9-CM 243 (congenital hypothyroidsm). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.