N91Header code — not billable

Absent, scanty and rare menstruation

Chapter
14. Diseases of the genitourinary system
Category
N91
Effective date
October 1, 2026

Related codes in category N91

N91.0Primary amenorrheaYesN91.1Secondary amenorrheaYesN91.2Amenorrhea, unspecifiedYesN91.3Primary oligomenorrheaYesN91.4Secondary oligomenorrheaYesN91.5Oligomenorrhea, unspecifiedYes

Frequently asked questions

What is ICD-10 code N91?

N91 is an ICD-10-CM diagnosis code for Absent, scanty and rare menstruation.

Is N91 a billable code?

No. N91 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is N91 in?

N91 falls under Chapter 14: Diseases of the genitourinary system.

When did N91 become effective?

N91 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to N91?

N91 belongs to category N91, which includes 6 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.