2026 ICD-10-CM Diagnosis Code E04.1Nontoxic single thyroid nodule
ICD-10-CM Codes›E00–E89›E00-E07›E04
- Billable — Valid for Submission
- Chronic Condition
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 11 through 13, 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.
E04.1 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
E04.1 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
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
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Struma See Also: Goiter;
uninodular E04.1
Thyroid (gland) (body) See Also: condition;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
Code HistoryHistory
Questions About E04.1Overview
What is the ICD-10 code for nontoxic single thyroid nodule?
The ICD-10-CM code for nontoxic single thyroid nodule is E04.1 (sometimes written as E041). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
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 11, 12, 13, 643, 644, 645, with relative weights from 0.7683 to 5.4541 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.
Does E04.1 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: E04.1 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 (Thyroid Disorders).
