2027 ICD-10-CM Diagnosis Code Q23.9Congenital malformation of aortic and mitral valves, unspecified
ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q23
- Billable — Valid for Submission
- POA Exempt
- Chronic Condition
Q23.9 is a billable ICD-10-CM diagnosis code for congenital malformation of aortic and mitral valves, 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. The code is exempt from POA reporting. Coders also document this condition as abnormality of mitral valve annulus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac and circulatory congenital anomalies.
Code Identity
Code Classification
Present on Admission (POA)Billing
Q23.9 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).
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormality of mitral valve annulus
- Abnormality of truncal valve cusp
- Congenital abnormality of aortic valve cusp
- Congenital anomaly of aortic valve
- Congenital anomaly of mitral valve
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Q23.9: 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.
Notes
General instructions on how these codes are used.
- Codes from this chapter are not for use on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name Q23.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming Q23.9: they are not reported together with it, unless the two conditions are unrelated.
- I34 Nonrheumatic mitral valve disordersmitral valve disorder specified as congenital (Q23.2, Q23.9)
Excludes2 1
These codes carry an Excludes2 note naming Q23.9: its condition is not part of those codes, and both may be reported when the patient has both.
Use Additional Code 1
These codes say to use an additional code from the note, and Q23.9 is one of the codes named.
- Q87.88 CTNNB1 syndrome
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Malformation (congenital) See Also: Anomaly;
aortic valve Q23.9
mitral valve Q23.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 Q23.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About Q23.9Overview
What is the ICD-10 code for congenital malformation of aortic and mitral valves, unspecified?
The ICD-10-CM code for congenital malformation of aortic and mitral valves, unspecified is Q23.9 (sometimes written as Q239). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is Q23.9 (Congenital malformations of aortic and mitral valves) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report congenital malformation of aortic and mitral valves, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does Q23.9 group to?
When congenital malformation of aortic and mitral valves, 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 Q23.9 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 aortic and mitral valves, unspecified on inpatient claims. The code appears in the Congenital malformations of the circulatory system (Q20-Q28) range of the CMS exempt list.
What is the ICD-9 equivalent of Q23.9?
Under the General Equivalence Mappings, congenital malformation of aortic and mitral valves, unspecified converts to ICD-9-CM 746.89 (cong heart anomaly NEC). The mapping is approximate, so confirm the match fits the documentation.
