ICD-10-CM Tabular Index · Chapter 14 · FY 2026 N91

Absent, scanty and rare menstruation (N91) ICD-10-CM

The N91 code range covers absent, scanty and rare menstruation with 7 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
7
Diagnosis Codes
6
Billable Codes
N91
Code Range
N80–N98
Parent Section

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

ICD-10-CM

Codes in the N91 Range 7 codes · 6 billable

7 of 7 shown
  • N91 Absent, scanty and rare menstruationNon-billable
  • N91.0 Primary amenorrhea
  • N91.1 Secondary amenorrhea
  • N91.2 Amenorrhea, unspecified
  • N91.3 Primary oligomenorrhea
  • N91.4 Secondary oligomenorrhea
  • N91.5 Oligomenorrhea, unspecified

Clinical Terms in This Code Range

Definitions from the National Library of Medicine for conditions coded in the N91 range.

Amenorrhea

Absence of menstruation.

Oligomenorrhea

Abnormally infrequent menstruation.

About the N91 Code Range

The ICD-10 codes N91 cover conditions involving absent, scanty, or infrequent menstruation. These codes specifically identify types of amenorrhea and oligomenorrhea, helping healthcare providers classify menstrual disorders accurately.

The ICD-10 code for absent menstruation includes N91.0 for primary amenorrhea, which refers to delayed or absent first menstrual periods, also known as physiologic or primary physiologic amenorrhea. N91.1 represents secondary amenorrhea, describing the loss of menstruation after it has previously occurred; this may be linked to several causes such as pituitary dysfunction, exercise-related amenorrhea, or lactational amenorrhea. When the cause is unclear, N91.2 is used for unspecified amenorrhea. Infrequent or scanty menstruation is classified under N91.3 and N91.4 for primary and secondary oligomenorrhea respectively, with N91.5 addressing unspecified cases. These codes aid medical coders and clinicians in accurately documenting menstrual irregularities, ensuring proper diagnosis and treatment planning.

Questions About This Page

How many billable codes are in the N91 range?

Of the 7 codes in this range, 6 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.

What does the N91 range classify?

The range classifies absent, scanty and rare menstruation. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.

Related References

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.