2026 ICD-10-CM Diagnosis Code O03.4Incomplete spontaneous abortion without complication

ICD-10-CM Codes›O00-O9A›O00-O08›O03

ICD-10-CM O03.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O03.4 is a billable ICD-10-CM diagnosis code for incomplete spontaneous abortion without complication. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as incomplete miscarriage. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Spontaneous abortion and complications of spontaneous abortion.

Code Identity

ICD-10-CM Code
O03.4
Billable Status
Yes — Valid for Submission
Code Describes
Incomplete spontaneous abortion without complication
Short Description
Incomplete spontaneous abortion without complication
Same as the full description in the CMS dataset.
Parent Code
O03
Spontaneous abortion

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO00-O08Pregnancy with abortive outcome
CategoryO03Spontaneous abortion
This CodeO03.4Incomplete spontaneous abortion without complication

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O03.4.

Maternity diagnoses
The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Incomplete miscarriage
  • Inevitable miscarriage
  • Inevitable miscarriage incomplete
  • Retained fetal tissue
  • Retained products after miscarriage

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abortion(complete) (spontaneous)
      • incomplete (spontaneous)
    • Abortion(complete) (spontaneous)
      • inevitable

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR PRG003
Spontaneous abortion and complications of spontaneous abortion
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Miscarriage

A miscarriage is an unexpected loss of pregnancy before the 20th week. Most miscarriages happen very early in the pregnancy, often before a woman even knows she is pregnant.

The full article covers:

  • What is a miscarriage?
  • What causes a miscarriage?
  • What are the signs of a miscarriage?
  • How is a miscarriage diagnosed?
  • What is the treatment for a miscarriage?
  • Can a miscarriage be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert O03.4 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
634.91 Spon abort uncompl-inc
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About O03.4Overview

Is O03.4 (Spontaneous abortion) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report incomplete spontaneous abortion without complication on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Who can O03.4 be reported for?

The Medicare Code Editor checks incomplete spontaneous abortion without complication against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.

What is the ICD-9 equivalent of O03.4?

Under the General Equivalence Mappings, incomplete spontaneous abortion without complication converts to ICD-9-CM 634.91 (spon abort uncompl-inc). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.