N91.4 Secondary oligomenorrhea

Billable ICD-10-CM code, FY2026.

Applies from N91 Absent, scanty and rare menstruation

Excludes1 (never code together)

• ovarian dysfunction (E28.-)

MS-DRG index

Defines the logic of DRG(s) 742-743 in MDC 13.

Approximate ICD-9-CM (GEMs)

• 626.1 Scanty or infrequent menstruation (approximate)

Code annotations containing back-references to N91.4

Back-references to N91.4

• Type 1 Excludes: N92.6 Irregular menstruation, unspecified ("lengthened intervals or scanty bleeding (N91.3-N91.5)")

Diagnosis Index entries for N91.4

• Oligomenorrhea › secondary

Nearby codes

• N91 Absent, scanty and rare menstruation
• N91.0 Primary amenorrhea
• N91.1 Secondary amenorrhea
• N91.2 Amenorrhea, unspecified
• N91.3 Primary oligomenorrhea
• N91.4 Secondary oligomenorrhea (this code)
• N91.5 Oligomenorrhea, unspecified