2026 ICD-10-CM Diagnosis Code O99.42Diseases of the circulatory system complicating childbirth

ICD-10-CM Codes›O00-O9A›O94-O9A›O99

ICD-10-CM O99.42
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O99.42 is a billable ICD-10-CM diagnosis code for diseases of the circulatory system complicating childbirth. 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). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complications specified during childbirth.

Code Identity

ICD-10-CM Code
O99.42
Billable Status
Yes — Valid for Submission
Code Describes
Diseases of the circulatory system complicating childbirth
Short Description
Diseases of the circulatory system complicating childbirth
Same as the full description in the CMS dataset.
Parent Code
O99.4
Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO94-O9AOther obstetric conditions, not elsewhere classified
CategoryO99Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
This CodeO99.42Diseases of the circulatory system complicating childbirth

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O99.42.

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.

  • Aortic valve disorder in mother complicating childbirth
  • Cardiac arrhythmia during pregnancy
  • Cardiac arrhythmia in mother complicating childbirth
  • Congenital cardiovascular anomaly in mother complicating childbirth
  • Congenital cardiovascular disorders during pregnancy, childbirth and the puerperium
  • Heart disease in mother complicating childbirth
  • Heart disease in mother complicating pregnancy, childbirth AND/OR puerperium
  • Heart murmur during pregnancy
  • Heart murmur in mother in childbirth
  • Mitral valve disorder in mother complicating childbirth

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.

    • Delivery(childbirth) (labor)
      • complicated
        • by
          • circulatory system disorder

Clinical ClassificationClinical

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

CCSR PRG023
Complications specified during childbirth
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Childbirth Problems

Childbirth is the process of giving birth to a baby. It includes labor and delivery. Usually everything goes well, but problems can happen. They may cause a risk to the mother, baby, or both. Some of the more common childbirth problems include:

Read the full article at MedlinePlus

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

Convert O99.42 to ICD-9-CMHistory

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

ICD-9-CM
674.01 Puerp cerebvas dis-deliv
Approximate The match is approximate rather than exact.
ICD-9-CM
674.02 Cerebvas dis-deliv w p/p
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 O99.42Overview

Is O99.42 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report diseases of the circulatory system complicating childbirth on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Who can O99.42 be reported for?

The Medicare Code Editor checks diseases of the circulatory system complicating childbirth 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 O99.42?

Under the General Equivalence Mappings, diseases of the circulatory system complicating childbirth converts to ICD-9-CM 674.01 (puerp cerebvas dis-deliv) and 674.02 (cerebvas dis-deliv w p/p). 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.