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N91.0 ICD-10-CM Code: Primary amenorrhea

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 Excludes1

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 742 — UTERINE AND ADNEXA PROCEDURES FOR NON-MALIGNANCY WITH CC/MCC (MDC 13)
  • MS-DRG 743 — UTERINE AND ADNEXA PROCEDURES FOR NON-MALIGNANCY WITHOUT CC/MCC (MDC 13)
  • MS-DRG 760 — MENSTRUAL AND OTHER FEMALE REPRODUCTIVE SYSTEM DISORDERS WITH CC/MCC (MDC 13)
  • MS-DRG 761 — MENSTRUAL AND OTHER FEMALE REPRODUCTIVE SYSTEM DISORDERS WITHOUT CC/MCC (MDC 13)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for N91.0 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on N91.0 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from N91

Coder workflow for N91.0

MedCoder structured workflow — derived from this code’s own official record

Before you code N91.0

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with N91.0. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in N91.0’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewE28

Consider N91.0. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Official instructions as workflow

  • Excludes1 — check before selecting N91.0(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with N91.0: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareE28

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition N91.0 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewE28

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Primary amenorrhea is a billable ICD-10-CM diagnosis code (N91.0).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (4)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 4 MS-DRGs: DRG 742 (MDC 13), DRG 743 (MDC 13), DRG 760 (MDC 13), DRG 761 (MDC 13).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):GEN021 — Menstrual disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Menstrual disorders).

N89.7 — Hematocolpos, N91.1 — Secondary amenorrhea, N91.2 — Amenorrhea, unspecified, N91.3 — Primary oligomenorrhea, N91.4 — Secondary oligomenorrhea, N91.5 — Oligomenorrhea, unspecified, N92.0 — Excessive and frequent menstruation with regular cycle, N92.1 — Excessive and frequent menstruation with irregular cycle, N92.2 — Excessive menstruation at puberty, N92.3 — Ovulation bleeding, N92.5 — Other specified irregular menstruation, N92.6 — Irregular menstruation, unspecified, N94.4 — Primary dysmenorrhea, N94.5 — Secondary dysmenorrhea, N94.6 — Dysmenorrhea, unspecified

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Menstruation”, “Failure, failed”; these codes share that main term but sit in a different category of the Tabular List.

M27.69 — Other endosseous dental implant failure (dental implant), N17.0 — Acute kidney failure with tubular necrosis (renal, with, tubular necrosis), N17.1 — Acute kidney failure with acute cortical necrosis (renal, acute, with, cortical necrosis), N17.2 — Acute kidney failure with medullary necrosis (renal, acute, with, medullary necrosis), N17.8 — Other acute kidney failure (renal, acute, specified NEC), N17.9 — Acute kidney failure, unspecified (renal, acute), N18.6 — End stage renal disease (renal, end stage), N18.9 — Chronic kidney disease, unspecified (renal, chronic), N19 — Unspecified kidney failure (renal), N52.9 — Male erectile dysfunction, unspecified (erection), N92.0 — Excessive and frequent menstruation with regular cycle (frequent), N92.1 — Excessive and frequent menstruation with irregular cycle (excessive, with irregular cycle), N92.2 — Excessive menstruation at puberty (excessive, at puberty), N92.5 — Other specified irregular menstruation (latent), N92.6 — Irregular menstruation, unspecified (irregular), N93.9 — Abnormal uterine and vaginal bleeding, unspecified (disorder), N94.4 — Primary dysmenorrhea (painful, primary), N94.5 — Secondary dysmenorrhea (painful, secondary), N94.6 — Dysmenorrhea, unspecified (painful), N94.89 — Other specified conditions associated with female genital organs and menstrual cycle (retained), +165 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Blood Glucose Test, Iron Panel, Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of N91.0 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 13 — Diseases and Disorders of the Female Reproductive System[MDC crossing]: “Diseases and Disorders of the Female Reproductive System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 2,232 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Amenorrhea, primary[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Delay, delayed, menstruation (cause unknown)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Failure, failed, menstruation at puberty[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Menstruation, delayed[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "N91.0 — Primary amenorrhea." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/n91.0-primary-amenorrhea

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Primary amenorrhea

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to N91.0 in its code family, with their registry titles.

View all codes in the N91 family