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O21.2 ICD-10-CM Code: Late vomiting of pregnancy

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

Coding at a Glance

Tabular directives
1 inclusion term · 2 Excludes2

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 v44, Appendix B.

  • MS-DRG 817 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 818 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 819 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)
  • MS-DRG 831 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 832 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 833 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)

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 O21.2 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on O21.2 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Excessive vomiting starting after 20 completed weeks of gestation

Excludes2 — Not Included Here

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

Source: inherited from O20-O29

Coder workflow for O21.2

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

Before you code O21.2

  1. Confirm the condition is documented as complicating the pregnancy, childbirth, or the puerperium, and check the trimester where the code carries one and the fetus character where the category requires it. Chapter 15 codes belong on the maternal record only and take sequencing priority over codes from other chapters. It is the provider’s responsibility to state that a condition is not affecting the pregnancy; the trimester is assigned from the documentation (Guidelines I.C.15.a, I.C.15.a.1, I.C.15.a.3).

    Guide: How to choose an ICD-10-CM code →

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).
Trimester
Assigned from the documented trimester at the encounter, or the trimester in which the condition developed for inpatient stays (Guidelines I.C.15.a.3).

Official instructions as workflow

  • Excludes2 — not part of O21.2(2 notes)

    Coding workflow: The conditions named in this note are not included in O21.2. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    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.

Don’t confuse O21.2 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of O21.2 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • O21.9— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Vomiting of pregnancy, unspecified” takes O21.9; specificity in the record moves it back here.

    Full comparison: O21.2 vs O21.9 →

  • O30— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal care related to the fetus and amniotic cavity and possible delivery problems adds O30; it is not part of this code and both may be reported when both are documented.

    Full comparison: O21.2 vs O30 →

  • O48— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal care related to the fetus and amniotic cavity and possible delivery problems adds O48; it is not part of this code and both may be reported when both are documented.

    Full comparison: O21.2 vs O48 →

  • O98— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium adds O98; it is not part of this code and both may be reported when both are documented.

    Full comparison: O21.2 vs O98 →

  • O99— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium adds O99; it is not part of this code and both may be reported when both are documented.

    Full comparison: O21.2 vs O99 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

Late vomiting of pregnancy is a billable ICD-10-CM diagnosis code (O21.2).

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 (1)

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

  • Age-restricted: the Medicare Code Editor lists this as a maternity (age 9-64) diagnosis; other ages are presumed incorrect.

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 O21.2 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 1 Excludes1 note: R11 — Nausea and vomiting (via O21.-).

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

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 6 MS-DRGs: DRG 817 (MDC 14), DRG 818 (MDC 14), DRG 819 (MDC 14), DRG 831 (MDC 14), DRG 832 (MDC 14), DRG 833 (MDC 14).

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

Clinical classification (AHRQ CCSR):PRG028 — Other specified complications in pregnancy (default); SYM004 — Nausea and vomiting.

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 categories (Other specified complications in pregnancy, Nausea and vomiting).

G43.A0 — Cyclical vomiting, in migraine, not intractable, G43.A1 — Cyclical vomiting, in migraine, intractable, K91.0 — Vomiting following gastrointestinal surgery, O21.8 — Other vomiting complicating pregnancy, O21.9 — Vomiting of pregnancy, unspecified, R11.0 — Nausea, R11.10 — Vomiting, unspecified, R11.11 — Vomiting without nausea, R11.12 — Projectile vomiting, R11.13 — Vomiting of fecal matter, R11.14 — Bilious vomiting, R11.15 — Cyclical vomiting syndrome unrelated to migraine, R11.16 — Cannabis hyperemesis syndrome, R11.2 — Nausea with vomiting, unspecified, +316 more

Contextual Map

Every relationship of O21.2 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 O21.2 with this related code in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • R11 — Nausea and vomiting[Excludes1](via O21.-): “excessive vomiting in pregnancy (O21.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 14 — Pregnancy, Childbirth and the Puerperium[MDC crossing]: “Pregnancy, Childbirth and the Puerperium — 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. 94 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Pregnancy (single) (uterine), complicated by (care of) (management affected by), vomiting, late (occurring after 20 weeks of gestation)[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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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. "O21.2 — Late vomiting of pregnancy." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/o21.2-late-vomiting-of-pregnancy

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Late vomiting of pregnancy

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, 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 O21.2 in its code family, with their registry titles.

View all codes in the O21 family