DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

O21 Excessive vomiting in pregnancy

  • Header · not billable

O21 is not billable. The category heads 5 billable codes in FY2027: the 5 codes directly below it.

Index → code

  • Hyperemesisgravidarum (mild) → O21.0
  • Imbalanceelectrolytedue to hyperemesis gravidarum → O21.1
  • Hyperemesisgravidarum (mild)severe (with metabolic disturbance) → O21.1

Where it sits

  1. Chapter 15 Pregnancy, childbirth and the puerperium (O00-O9A)
  2. O20-O29 Other maternal disorders predominantly related to pregnancy (O20-O29)
  3. O21 Excessive vomiting in pregnancy
Billable codes
5
Subdivisions
5
CC / MCC codes
0 / 0
HCC V28 codes
0
New FY2027
0
Index entries
12

Codes in O21

  1. O21.0
    Mild hyperemesis gravidarum
    Billable
    Inclusion terms 1

    Inclusion terms

    • Hyperemesis gravidarum, mild or unspecified, starting before the end of the 20th week of gestation
  2. O21.1
    Hyperemesis gravidarum with metabolic disturbance
    Billable
    Inclusion terms 3

    Inclusion terms

    • Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as carbohydrate depletion
    • Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as dehydration
    • Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as electrolyte imbalance
  3. O21.2
    Late vomiting of pregnancy
    Billable
    Inclusion terms 1

    Inclusion terms

    • Excessive vomiting starting after 20 completed weeks of gestation
  4. O21.8
    Other vomiting complicating pregnancy
    Billable
    Inclusion terms 1, Use additional code 1

    Inclusion terms

    • Vomiting due to diseases classified elsewhere, complicating pregnancy

    Use additional code

    • code, to identify cause.
  5. O21.9
    Vomiting of pregnancy, unspecified
    Billable

Sources of each column.

Instructions

Notes that also apply

Block O20-O29 instructions (Excludes2 2): printed on the block page.

Chapter 15 instructions (Notes 6, Excludes1 1, Excludes2 4, Use additional code 1): printed on the chapter 15 page.

Index entries

  • Hyperemesisgravidarum (mild) → O21.0
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)hyperemesis (gravidarum) (mild) → O21.0-
  • Hyperemesisgravidarum (mild)severe (with metabolic disturbance) → O21.1
  • Imbalanceelectrolytedue to hyperemesis gravidarum → O21.1
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)vomiting → O21.9
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)vomitinghyperemesis gravidarum (mild) → O21.0-
  • Hyperemesisgravidarum (mild)withcarbohydrate depletion → O21.1
  • Hyperemesisgravidarum (mild)withdehydration → O21.1
  • Hyperemesisgravidarum (mild)withelectrolyte imbalance → O21.1
  • Hyperemesisgravidarum (mild)withmetabolic disturbance → O21.1
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)vomitinglate (occurring after 20 weeks of gestation) → O21.2
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)vomitingdue to diseases classified elsewhere → O21.8

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy