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Q91.2 ICD-10-CM Code: Trisomy 18, translocation

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

Coding at a Glance

Tabular directives
1 Excludes2
Risk adjustment
RxHCC V08 category 148

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 884 — ORGANIC DISTURBANCES AND INTELLECTUAL DISABILITY (MDC 19)

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 Q91.2 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 Q91.2 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from Q90-Q99

Coder workflow for Q91.2

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

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

  • Excludes2 — not part of Q91.2(1 note)

    Coding workflow: The conditions named in this note are not included in Q91.2. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareE88.4

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

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

Trisomy 18, translocation is a billable ICD-10-CM diagnosis code (Q91.2).

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 (3)

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

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

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

Other codes that name Q91.2 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 11 Excludes1 notes across 3 chapters: E25 — Adrenogenital disorders (via Q91.-), Q50 — Congenital malformations of ovaries, fallopian tubes and broad ligaments (via Q91.-), Q50-Q56 — Congenital malformations of genital organs (Q50-Q56) (via Q91.-), Q51 — Congenital malformations of uterus and cervix (via Q91.-), Q52 — Other congenital malformations of female genitalia (via Q91.-), Q53 — Undescended and ectopic testicle (via Q91.-), Q54 — Hypospadias (via Q91.-), Q55 — Other congenital malformations of male genital organs (via Q91.-), Q56 — Indeterminate sex and pseudohermaphroditism (via Q91.-), Q92 — Other trisomies and partial trisomies of the autosomes, not elsewhere classified (via Q91.-), Z15 — Genetic susceptibility to disease (via Q91.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Code First instruction: D84.81 — Immunodeficiency due to conditions classified elsewhere (via Q91.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 68 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 1 MS-DRG: DRG 884 (MDC 19).

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

Clinical classification (AHRQ CCSR):MAL009 — Chromosomal abnormalities (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 process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

Q90.0 — Trisomy 21, nonmosaicism (meiotic nondisjunction), Q90.1 — Trisomy 21, mosaicism (mitotic nondisjunction), Q90.2 — Trisomy 21, translocation, Q90.9 — Down syndrome, unspecified, Q91.0 — Trisomy 18, nonmosaicism (meiotic nondisjunction), Q91.1 — Trisomy 18, mosaicism (mitotic nondisjunction), Q91.3 — Trisomy 18, unspecified, Q91.4 — Trisomy 13, nonmosaicism (meiotic nondisjunction), Q91.5 — Trisomy 13, mosaicism (mitotic nondisjunction), Q91.6 — Trisomy 13, translocation, Q91.7 — Trisomy 13, unspecified, Q92.0 — Whole chromosome trisomy, nonmosaicism (meiotic nondisjunction), Q92.1 — Whole chromosome trisomy, mosaicism (mitotic nondisjunction), Q92.2 — Partial trisomy, Q92.5 — Duplications with other complex rearrangements, Q92.61 — Marker chromosomes in normal individual, Q92.62 — Marker chromosomes in abnormal individual, Q92.7 — Triploidy and polyploidy, Q92.8 — Other specified trisomies and partial trisomies of autosomes, Q92.9 — Trisomy and partial trisomy of autosomes, unspecified, +47 more

Same clinical category (CCSR)

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

Q87.86 — Kleefstra syndrome, Q90.0 — Trisomy 21, nonmosaicism (meiotic nondisjunction), Q90.1 — Trisomy 21, mosaicism (mitotic nondisjunction), Q90.2 — Trisomy 21, translocation, Q90.9 — Down syndrome, unspecified, Q91.0 — Trisomy 18, nonmosaicism (meiotic nondisjunction), Q91.1 — Trisomy 18, mosaicism (mitotic nondisjunction), Q91.3 — Trisomy 18, unspecified, Q91.4 — Trisomy 13, nonmosaicism (meiotic nondisjunction), Q91.5 — Trisomy 13, mosaicism (mitotic nondisjunction), Q91.6 — Trisomy 13, translocation, Q91.7 — Trisomy 13, unspecified, Q92.0 — Whole chromosome trisomy, nonmosaicism (meiotic nondisjunction), Q92.1 — Whole chromosome trisomy, mosaicism (mitotic nondisjunction), Q92.2 — Partial trisomy, Q92.5 — Duplications with other complex rearrangements, Q92.61 — Marker chromosomes in normal individual, Q92.62 — Marker chromosomes in abnormal individual, Q92.7 — Triploidy and polyploidy, Q92.8 — Other specified trisomies and partial trisomies of autosomes, +56 more

Same Index main term, other category

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

Q90.0 — Trisomy 21, nonmosaicism (meiotic nondisjunction) (21, meiotic nondisjunction), Q90.1 — Trisomy 21, mosaicism (mitotic nondisjunction) (21, mosaicism), Q90.2 — Trisomy 21, translocation (trisomy, 21), Q90.9 — Down syndrome, unspecified (21), Q92.0 — Whole chromosome trisomy, nonmosaicism (meiotic nondisjunction) (whole chromosome, meiotic nondisjunction), Q92.1 — Whole chromosome trisomy, mosaicism (mitotic nondisjunction) (whole chromosome, mosaicism), Q92.2 — Partial trisomy (chromosome specified NEC, partial), Q92.5 — Duplications with other complex rearrangements (chromosome specified NEC, partial, due to unbalanced translocation), Q92.8 — Other specified trisomies and partial trisomies of autosomes (20), Q92.9 — Trisomy and partial trisomy of autosomes, unspecified, Q95.0 — Balanced translocation and insertion in normal individual (balanced autosomal, in normal individual), Q95.9 — Balanced rearrangement and structural marker, unspecified (balanced autosomal), Q99.8 — Other specified chromosome abnormalities (chromosomes NEC)

Contextual Map

Every relationship of Q91.2 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.

Run Q91.2 with these 9 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes (11)

Referenced by Code First instructions

Clinical classification (CCSR)

MS-DRG Grouper

  • CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
  • DRG 884 — ORGANIC DISTURBANCES AND INTELLECTUAL DISABILITY[MS-DRG]: “ORGANIC DISTURBANCES AND INTELLECTUAL DISABILITY (MDC 19)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

  • MDC 19 — Mental Diseases and Disorders[MDC crossing]: “Mental Diseases and Disorders — 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.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Syndrome, trisomy, 18, translocation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Translocation, trisomy, 18[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Trisomy (syndrome), 18 (partial), translocation[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. "Q91.2 — Trisomy 18, translocation." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/q91.2-trisomy-18-translocation

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Trisomy 18, translocation

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 Q91.2 in its code family, with their registry titles.

View all codes in the Q91 family