2026 ICD-10-CM Diagnosis Code E04.1Nontoxic single thyroid nodule

ICD-10-CM Codes›E00–E89›E00-E07›E04

ICD-10-CM E04.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E04.1 is a billable ICD-10-CM diagnosis code for nontoxic single thyroid nodule. 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 calcifying cyst of thyroid. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

Code Identity

ICD-10-CM Code
E04.1
Billable Status
Yes — Valid for Submission
Code Describes
Nontoxic single thyroid nodule
Short Description
Nontoxic single thyroid nodule
Same as the full description in the CMS dataset.
Parent Code
E04
Other nontoxic goiter

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE00-E07Disorders of thyroid gland
CategoryE04Other nontoxic goiter
This CodeE04.1Nontoxic single thyroid nodule

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Calcifying cyst of thyroid
  • Cyst of thyroid
  • Dominant nodule of thyroid
  • Hyperplastic thyroid nodule
  • Non-toxic uninodular goiter
  • Thyroid hormone tests within reference range
  • Thyroid nodule
  • Uninodular goiter

Tabular List NotesGuidance

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

Inclusion Terms

  • Colloid nodule (cystic) (thyroid)
  • Nontoxic uninodular goiter
  • Thyroid (cystic) nodule 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.

    • Colloid nodule(of thyroid) (cystic)
    • Cyst(colloid) (mucous) (simple) (retention)
      • thyroid (gland)
    • Goiter(plunging) (substernal)
      • nontoxic
        • uninodular
    • Goiter(plunging) (substernal)
      • uninodular (nontoxic)
    • Nodule(s), nodular
      • colloid (cystic), thyroid
    • Nodule(s), nodular
      • thyroid (cold) (gland) (nontoxic)
    • Struma
      • nodosa (simplex)
        • uninodular
    • Thyroid(gland) (body)
      • nodule (cystic) (nontoxic) (single)

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

  • Thyroid Nodule

    a small circumscribed mass in the thyroid gland that can be of neoplastic growth or non-neoplastic abnormality. it lacks a well-defined capsule or glandular architecture. thyroid nodules are often benign but can be malignant. the growth of nodules can lead to a multinodular goiter (goiter, nodular).

  • Uninodular Goiter

    nodular goiter characterized by one discrete tissue mass.

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 E04.1 to ICD-9-CMHistory

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

ICD-9-CM
241.0 Nontox uninodular goiter
Approximate The match is approximate rather than exact.
ICD-9-CM
246.2 Cyst of thyroid
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 E04.1Overview

Is E04.1 (Other nontoxic goiter) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nontoxic single thyroid nodule on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E04.1 group to?

When nontoxic single thyroid nodule 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 E04.1?

Under the General Equivalence Mappings, nontoxic single thyroid nodule converts to ICD-9-CM 241.0 (nontox uninodular goiter) and 246.2 (cyst of thyroid). 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.