2027 ICD-10-CM Diagnosis Code O99.43Diseases of the circulatory system complicating the puerperium

ICD-10-CM Codes›O00-O9A›O94-O9A›O99

ICD-10-CM O99.43
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O99.43 is a billable ICD-10-CM diagnosis code for diseases of the circulatory system complicating the puerperium. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 769, 776. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 227 closely related codes. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as cerebrovascular disorder in the puerperium. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complications specified during the puerperium.

Code Identity

ICD-10-CM Code
O99.43
Billable Status
Yes — Valid for Submission
Code Describes
Diseases of the circulatory system complicating the puerperium
Short Description
Diseases of the circ sys complicating the puerperium
Parent Code
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 CodeO99.43Diseases of the circulatory system complicating the puerperium

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O99.43.

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.

  • Cerebrovascular disorder in the puerperium
  • Heart disease in mother complicating pregnancy, childbirth AND/OR puerperium
  • Postpartum heart murmur
  • Stroke in the puerperium

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O99.43: its own notes plus those printed at O99.4, O99, and Chapter 15. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium applies to 96 codes
  • conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium applies to 6 codes
  • peripartum cardiomyopathy (O90.3)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium applies to 6 codes
  • hypertensive disorders (O10-O16)
  • obstetric embolism (O88.-)
  • venous complications and cerebrovenous sinus thrombosis in labor, childbirth and the puerperium (O87.-)
  • venous complications and cerebrovenous sinus thrombosis in pregnancy (O22.-)
From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium applies to 96 codes
  • when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium applies to 96 codes
  • code to identify specific condition
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O99.43, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming O99.43: they are not reported together with it, unless the two conditions are unrelated.

  • O90.3 Peripartum cardiomyopathy
    pre-existing heart disease complicating pregnancy and the puerperium (O99.4-) names O99.4-, which includes this code

Code First 1

These codes say to code first a condition named in the note, and O99.43 is one of the conditions named.

  • I42 Cardiomyopathy
    pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4) names O99.4, which includes this code

Index to Diseases and InjuriesGuidance

Clinical ClassificationClinical

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

CCSR PRG027
Complications specified during the puerperium
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Heart Diseases

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

The full article covers:

  • What is heart disease?
  • What are the types of heart disease?
  • What causes heart diseases?
  • Who is more likely to develop heart diseases?
  • What are the symptoms of heart disease?
  • How are heart diseases diagnosed?
  • What are the treatments for heart disease?
  • Can heart diseases be prevented?

Read the full article at MedlinePlus

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

Convert O99.43 to ICD-9-CMHistory

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

ICD-9-CM
674.04 Cerebrovasc dis-postpart
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O99.43Overview

What is the ICD-10 code for diseases of the circulatory system complicating the puerperium?

The ICD-10-CM code for diseases of the circulatory system complicating the puerperium is O99.43 (sometimes written as O9943). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is O99.43 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report diseases of the circulatory system complicating the puerperium on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does O99.43 group to?

When diseases of the circulatory system complicating the puerperium is the principal diagnosis on an inpatient stay, it groups to MS-DRG 769, 776, with relative weights from 0.6718 to 1.6666 depending on complications. Higher weights mean higher Medicare reimbursement.

Is O99.43 a CC or MCC?

CMS lists O99.43 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 227 closely related codes in its exclusion list.

Who can O99.43 be reported for?

The Medicare Code Editor checks diseases of the circulatory system complicating the puerperium against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.