ICD-10 Code E31.22 – Multiple endocrine neoplasia [MEN] type IIA (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E31.22 – Multiple endocrine neoplasia [MEN] type IIA
What it is
E31.22 identifies multiple endocrine neoplasia type IIA, an inherited syndrome that predisposes a person to tumors in multiple endocrine glands. It is used when the diagnosis is documented as MEN 2A or Multiple endocrine neoplasia [MEN] type IIA.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism in the setting of a hereditary endocrine syndrome.
When to use this code
Use this code when the provider documents MEN type IIA, MEN 2A, or a confirmed multiple endocrine neoplasia syndrome of this type. It may also apply when the record clearly links the patient’s endocrine tumors to this hereditary syndrome. Check documentation if the note only says “MEN” without specifying type.
Do not use for
Do not use this code for MEN type IIB, MEN type I, or isolated endocrine tumors without a documented MEN 2A diagnosis. If the subtype is unclear, check documentation.
Coding tip
Capture the exact MEN subtype from the provider note, because the code differs by syndrome type.