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Compare/O21 vs R11

O21 vs R11

O21 (Excessive vomiting in pregnancy) compared with R11 (Nausea and vomiting), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. R11 carries an Excludes1 note covering O21: “excessive vomiting in pregnancy (O21.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

O21Excessive vomiting in pregnancyR11Nausea and vomiting
Billing statusNon-billable header

Report instead: O21.0, O21.1, O21.2, O21.8, O21.9

Non-billable header

Report instead: R11.0, R11.10, R11.11, R11.12, R11.13

ClassificationO00-O9A — Pregnancy, Childbirth and the Puerperium (O00-O9A)R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99)
DefinitionExcessive vomiting in pregnancy is a non-billable ICD-10-CM category code (O21).Nausea and vomiting is a non-billable ICD-10-CM category code (R11).
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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources