2027 ICD-10-CM Diagnosis Code Q25.9Congenital malformation of great arteries, unspecified

ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q25

ICD-10-CM Q25.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q25.9 is a billable ICD-10-CM diagnosis code for congenital malformation of great arteries, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 306 through 307. 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 57 closely related codes. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac and circulatory congenital anomalies.

Code Identity

ICD-10-CM Code
Q25.9
Billable Status
Yes — Valid for Submission
Code Describes
Congenital malformation of great arteries, unspecified
Short Description
Congenital malformation of great arteries, unspecified
Same as the full description in the CMS dataset.
Parent Code
Q25
Congenital malformations of great arteries

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ20-Q28Congenital malformations of the circulatory system
CategoryQ25Congenital malformations of great arteries
This CodeQ25.9Congenital malformation of great arteries, unspecified

Present on Admission (POA)Billing

Q25.9 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Congenital malformations of the circulatory system (Q20-Q28).

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q25.9: its own notes plus those printed at Chapter 17. A note printed at a category, block or chapter applies to every code under it.

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 Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Notes

General instructions on how these codes are used.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • Codes from this chapter are not for use on maternal records

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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR MAL001
Cardiac and circulatory congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Congenital Heart Defects

Congenital heart defects (CHDs) are problems with the structure of the heart. "Congenital" means that that the problems are present at birth. These defects happen when a fetus's heart doesn't develop normally during pregnancy. Congenital heart defects are the most common type of birth defect.

The full article covers:

  • What are congenital heart defects?
  • What causes congenital heart defects?
  • Who is more likely to have a baby with a congenital heart defect?
  • What are the symptoms of congenital heart defects?
  • What other problems do congenital heart defects cause?
  • How are congenital heart defects diagnosed?
  • What are the treatments for congenital heart defects?

Read the full article at MedlinePlus

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

Convert Q25.9 to ICD-9-CMHistory

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

ICD-9-CM
747.29 Cong anom of aorta NEC
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 Q25.9Overview

What is the ICD-10 code for congenital malformation of great arteries, unspecified?

The ICD-10-CM code for congenital malformation of great arteries, unspecified is Q25.9 (sometimes written as Q259). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Q25.9 (Congenital malformations of great arteries) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report congenital malformation of great arteries, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does Q25.9 group to?

When congenital malformation of great arteries, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 306, 307, with relative weights from 0.9146 to 1.5457 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q25.9 a CC or MCC?

CMS lists Q25.9 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 57 closely related codes in its exclusion list.

Is Q25.9 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for congenital malformation of great arteries, unspecified on inpatient claims. The code appears in the Congenital malformations of the circulatory system (Q20-Q28) range of the CMS exempt list.