ICD-10 Code E31.20 – Multiple endocrine neoplasia [MEN] syndrome, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E31.20 – Multiple endocrine neoplasia [MEN] syndrome, unspecified
What it is
E31.20 identifies multiple endocrine neoplasia syndrome when the specific MEN type is not documented. Use it for a hereditary disorder that causes tumors or overactivity in more than one endocrine gland.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include endocrine tumors, gland enlargement, or hormone-related symptoms affecting more than one organ system.
When to use this code
Use E31.20 when the record states MEN syndrome but does not specify MEN1, MEN2, or another subtype. It also fits when the provider documents a suspected or established MEN syndrome without further detail. If the type is identified elsewhere in the chart, code the documented subtype instead.
Do not use for
Do not use this code for a single endocrine tumor without MEN syndrome. Check documentation if the provider names a specific MEN type, because an unspecified code may not be correct.
Coding tip
Code the most specific MEN type available; use E31.20 only when the documentation leaves the syndrome unspecified.