O21Header code — not billable

Excessive vomiting in pregnancy

Chapter
15. Pregnancy, childbirth and the puerperium
Category
O21
Effective date
October 1, 2026

Related codes in category O21

O21.0Mild hyperemesis gravidarumYesO21.1Hyperemesis gravidarum with metabolic disturbanceYesO21.2Late vomiting of pregnancyYesO21.8Other vomiting complicating pregnancyYesO21.9Vomiting of pregnancy, unspecifiedYes

Frequently asked questions

What is ICD-10 code O21?

O21 is an ICD-10-CM diagnosis code for Excessive vomiting in pregnancy.

Is O21 a billable code?

No. O21 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is O21 in?

O21 falls under Chapter 15: Pregnancy, childbirth and the puerperium.

When did O21 become effective?

O21 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to O21?

O21 belongs to category O21, which includes 5 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.