2026 ICD-10-CM Diagnosis Code E31.22Multiple endocrine neoplasia [MEN] type IIA

ICD-10-CM Codes›E00–E89›E20-E35›E31

ICD-10-CM E31.22
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E31.22 is a billable ICD-10-CM diagnosis code for multiple endocrine neoplasia [MEN] type IIA. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endocrine system cancers - thyroid and Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E31.22
Billable Status
Yes — Valid for Submission
Code Describes
Multiple endocrine neoplasia [MEN] type IIA
Short Description
Multiple endocrine neoplasia [MEN] type IIA
Same as the full description in the CMS dataset.
Parent Code
E31.2
Multiple endocrine neoplasia [MEN] syndromes

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE31Polyglandular dysfunction
This CodeE31.22Multiple endocrine neoplasia [MEN] type IIA

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Benign multiple endocrine neoplasia type 2a
  • Malignant multiple endocrine neoplasia type 2a
  • Multiple endocrine neoplasia type 2A
  • Multiple endocrine neoplasia, type 2
  • 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

  • Sipple's syndrome

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.

    • Neoplasia
      • endocrine, multiple (MEN)
        • type IIA
    • Sipple's syndrome
    • Syndrome
      • Sipple's

Clinical ClassificationClinical

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

CCSR NEO050
Endocrine system cancers - thyroid
Default principal diagnosis: inpatient No · outpatient No
CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Multiple Endocrine Neoplasia Type 2a

    a form of multiple endocrine neoplasia characterized by the presence of medullary carcinoma (carcinoma, medullary) of the thyroid gland, and usually with the co-occurrence of pheochromocytoma, producing calcitonin and adrenaline, respectively. less frequently, it can occur with hyperplasia or adenoma of the parathyroid glands. this disease is due to gain-of-function mutations of the men2 gene on chromosome 10 (locus: 10q11.2), also known as the ret proto-oncogene that encodes a receptor protein-tyrosine kinase. it is an autosomal dominant inherited disease.

  • Multiple Endocrine Neoplasia Type 2

    multiple endocrine neoplasia caused by mutation of the ret gene. it includes the following neoplastic processes: multiple endocrine neoplasia type 2a, multiple endocrine neoplasia type 2b, and hereditary thyroid gland medullary carcinoma.

  • Multiple Endocrine Neoplasia Type 2A|MEA Type 2a|MEA Type II|MEN 2A|MEN Type 2a|MEN Type II|Multiple Endocrine Adenomatosis Type 2A|Multiple Endocrine Adenomatosis Type 2a|Multiple Endocrine Adenomatosis Type II|Multiple Endocrine Adenomatosis, Type II|Multiple Endocrine Neoplasia Type 2a|Multiple Endocrine Neoplasia Type II|Multiple Endocrine Neoplasia, Type II|Multiple endocrine neoplasia [MEN] type IIA

    multiple endocrine neoplasia caused by mutation of the ret gene. patients develop medullary thyroid carcinomas, and may also develop pheochromocytomas and parathyroid gland hyperplasia.

  • Multiple Endocrine Neoplasia Type 2B|MEN 2B|MEN IIB|MEN Type 2B|MEN Type IIB|Multiple Endocrine Adenomatosis Type IIB|Multiple Endocrine Neoplasia Type 2b|Multiple Endocrine Neoplasia Type 3|Multiple Endocrine Neoplasia Type IIB|Multiple Endocrine Neoplasia Type III|Multiple Endocrine Neoplasia, Type III|Multiple endocrine neoplasia [MEN] type IIB

    multiple endocrine neoplasia caused by mutation of the ret gene. patients develop medullary thyroid carcinomas and numerous neural defects including neuromas.

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

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Convert E31.22 to ICD-9-CMHistory

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

ICD-9-CM
258.02 Mult endo neop type IIA
Exact Match The mapping is direct, with no qualifiers.

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 E31.22Overview

Is E31.22 (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] type IIA on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E31.22 group to?

When multiple endocrine neoplasia [MEN] type IIA 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 E31.22?

Under the General Equivalence Mappings, multiple endocrine neoplasia [MEN] type IIA converts to ICD-9-CM 258.02 (mult endo neop type IIA). The mapping is a direct match.

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.