O21.0 — Mild hyperemesis gravidarum

O21.0

ICD-10 Chapter 15: Pregnancy, Childbirth & Puerperium — illustrative image — Chapter 15: Pregnancy, childbirth and the puerperium (O00–O9A) — illustrative image

What this code means

Mild hyperemesis gravidarum is excessive vomiting in pregnancy beyond ordinary morning sickness, without metabolic disturbance.

Also called: hyperemesis gravidarum, severe morning sickness.

When this code is used

Used for mild hyperemesis gravidarum.

Where it sits in ICD-10-CM

Code O21.0 belongs to Chapter 15: Pregnancy, childbirth and the puerperium, which covers codes O00–O9A in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Learn more about this condition

Condition guide: Pregnancy

Related symptoms

Frequently asked questions

What is ICD-10-CM code O21.0?

O21.0 is the ICD-10-CM diagnosis code for “Mild hyperemesis gravidarum”. Mild hyperemesis gravidarum is excessive vomiting in pregnancy beyond ordinary morning sickness, without metabolic disturbance.

When is code O21.0 used?

Used for mild hyperemesis gravidarum. It belongs to Chapter 15 of ICD-10-CM (Pregnancy, childbirth and the puerperium).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.