O20.0 Threatened abortion

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Hemorrhage specified as due to threatened abortion

Applies from O20 Hemorrhage in early pregnancy

Includes

• hemorrhage before completion of 20 weeks gestation

Excludes1 (never code together)

• pregnancy with abortive outcome (O00-O08)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 640.03 Threatened abortion, 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 O20.0

Back-references to O20

• Type 1 Excludes: O46 Antepartum hemorrhage, not elsewhere classified ("hemorrhage in early pregnancy (O20.-)")

Diagnosis Index entries for O20.0

• Abortion (complete) (spontaneous) › spontaneous › threatened
• Abortion (complete) (spontaneous) › threatened (spontaneous)
• Hemorrhage, hemorrhagic (concealed) › antepartum (with) › before 20 weeks gestation › threatened abortion
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › hemorrhage › threatened abortion
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › threatened › abortion
• Threatened › abortion
• Threatened › miscarriage

Nearby codes

• O20 Hemorrhage in early pregnancy
• O20.0 Threatened abortion (this code)
• O20.8 Other hemorrhage in early pregnancy
• O20.9 Hemorrhage in early pregnancy, unspecified