2026 ICD-10-CM Diagnosis Code D44.0Neoplasm of uncertain behavior of thyroid gland

ICD-10-CM Codes›C00–D49›D37-D48›D44

ICD-10-CM D44.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D44.0 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of thyroid gland. 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 neoplasm of thyroglossal duct. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D44.0
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior of thyroid gland
Short Description
Neoplasm of uncertain behavior of thyroid gland
Same as the full description in the CMS dataset.
Parent Code
D44
Neoplasm of uncertain behavior of endocrine glands

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD44Neoplasm of uncertain behavior of endocrine glands
This CodeD44.0Neoplasm of uncertain behavior of thyroid gland

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neoplasm of thyroglossal duct
  • Neoplasm of uncertain behavior of thyroglossal duct
  • Neoplasm of uncertain behavior of thyroid gland

Clinical ClassificationClinical

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

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
thyroglossal ductC73C79.89D09.3D34D44.0D49.7
thyroid (gland)C73C79.89D09.3D34D44.0D49.7

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 D44.0 to ICD-9-CMHistory

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

ICD-9-CM
237.4 Uncer neo endocrine NEC
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 D44.0Overview

Is D44.0 (Neoplasm of uncertain behavior of endocrine glands) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior of thyroid gland on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D44.0 group to?

When neoplasm of uncertain behavior of thyroid gland 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 D44.0?

Under the General Equivalence Mappings, neoplasm of uncertain behavior of thyroid gland converts to ICD-9-CM 237.4 (uncer neo endocrine NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.