O21.9 Vomiting of pregnancy, unspecified

Billable ICD-10-CM code, FY2026.

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 643.93 Unspecified vomiting of pregnancy, antepartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O21.9

Back-references to O21

• Type 1 Excludes: R11 Nausea and vomiting ("excessive vomiting in pregnancy (O21.-)")

Diagnosis Index entries for O21.9

• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › vomiting

Nearby codes

• O21 Excessive vomiting in pregnancy
• O21.0 Mild hyperemesis gravidarum
• O21.1 Hyperemesis gravidarum with metabolic disturbance
• O21.2 Late vomiting of pregnancy
• O21.8 Other vomiting complicating pregnancy
• O21.9 Vomiting of pregnancy, unspecified (this code)