ICD10BillableValid for clinical use

ICD-10 Code N91.5: Oligomenorrhea, unspecified

N91.5 is a billable ICD-10 diagnosis code used to classify Oligomenorrhea, unspecified in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

When is it used?

  • May be used when a clinician documents oligomenorrhea, unspecified in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
14Diseases of the genitourinary system (N00-N99)
block
N80-N98Noninflammatory disorders of female genital tract
category
N91Absent, scanty and rare menstruation
currentN91

Official coding notes

Inclusion terms
  • Hypomenorrhea NOS

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

UrologistGynecologist

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
N91.5

Common synonyms

Oligomenorrhea, unspecifiedOligomenorrhea

Frequently asked questions

Code details

CodeN91.5
SystemICD10
Display nameOligomenorrhea, unspecified
ChapterDiseases of the genitourinary system (N00-N99)
BlockNoninflammatory disorders of female genital tract

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Oligomenorrhea

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code N91.5 for Oligomenorrhea, unspecified | HealthAssure