O21.0 Mild hyperemesis gravidarum

The ICD-10-CM code for Mild hyperemesis gravidarum is O21.0 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

15: Pregnancy, childbirth and the puerperium (O00-O9A)

Section

O20-O29: Other maternal disorders predominantly related to pregnancy (O20-O29)

Category O21

6 codes (5 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to O21.0:

• Hyperemesis › gravidarum (mild)
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › hyperemesis (gravidarum) (mild)
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › vomiting › hyperemesis gravidarum (mild)

Inclusion Terms

• Hyperemesis gravidarum, mild or unspecified, starting before the end of the 20th week of gestation

U.S. Hospital Utilization

• An estimated 11,095 U.S. inpatient stays in 2023 included O21.0 among the documented diagnoses.
• 5,315 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)