2027 ICD-10-CM Diagnosis Code D44.0Neoplasm of uncertain behavior of thyroid gland
ICD-10-CM Codes›C00–D49›D37-D48›D44
- Billable — Valid for Submission
- Not Chronic
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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 643 through 645. Coders also document this condition as follicular neoplasm of thyroid. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Follicular neoplasm of thyroid
- Follicular thyroid neoplasm of uncertain malignant potential
- Hyalinizing trabecular neoplasm of thyroid
- Neoplasm of thyroglossal duct
- Neoplasm of uncertain behavior of thyroglossal duct
- Neoplasm of uncertain behavior of thyroid gland
- Non-invasive follicular thyroid neoplasm with papillary like nuclear features
- Well-differentiated neoplasm of uncertain malignant potential of thyroid
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to D44.0: its own notes plus those printed at D44, block D37-D48, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- neoplasms of unspecified behavior (D49.-)
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name D44.0, its category, or a range that includes it.
Excludes2 1
These codes carry an Excludes2 note naming D44.0: its condition is not part of those codes, and both may be reported when the patient has both.
- D49 Neoplasms of unspecified behavior
Notes 1
These notes mention D44.0.
- Block D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
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.
Code HistoryHistory
Questions About D44.0Overview
What is the ICD-10 code for neoplasm of uncertain behavior of thyroid gland?
The ICD-10-CM code for neoplasm of uncertain behavior of thyroid gland is D44.0 (sometimes written as D440). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
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 644, 645, 643, with relative weights from 0.7461 to 1.6138 depending on complications. Higher weights mean higher Medicare reimbursement.
Can D44.0 be reported with a code from E31.2?
Not as a rule. The Excludes1 note at D44, which applies to D44.0, lists "multiple endocrine adenomatosis (E31.2-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
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.
