2026 ICD-10-CM Diagnosis Code E31.20Multiple endocrine neoplasia [MEN] syndrome, unspecified
ICD-10-CM Codes›E00–E89›E20-E35›E31
- Billable — Valid for Submission
- Chronic Condition
E31.20 is a billable ICD-10-CM diagnosis code for multiple endocrine neoplasia [MEN] 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 multiple endocrine neoplasia type 4. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Multiple endocrine neoplasia type 4
- Neoplasm of uncertain behavior of multiple endocrine glands
- Polyglandular activity in multiple endocrine adenomatosis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Multiple endocrine adenomatosis NOS
- Multiple endocrine neoplasia MEN syndrome 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.
- endocrine (multiple) - E31.20
- endocrine, multiple (MEN) - E31.20
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Adenomatosis
- endocrine (multiple)
- Neoplasia
- endocrine, multiple (MEN)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Endocrine Diseases
Your endocrine system includes eight major glands throughout your body. These glands make hormones. Hormones are chemical messengers. They travel through your bloodstream to tissues or organs. Hormones work slowly and affect body processes from head to toe. These include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert E31.20 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E31.20Overview
Is E31.20 (Multiple endocrine neoplasia [MEN] syndromes) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report multiple endocrine neoplasia [MEN] syndrome, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does E31.20 group to?
When multiple endocrine neoplasia [MEN] 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 E31.20?
Under the General Equivalence Mappings, multiple endocrine neoplasia [MEN] syndrome, unspecified converts to ICD-9-CM 258.8 (polyglandul dysfunc NEC). 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.
