2027 ICD-10-CM Diagnosis Code Q24.4Congenital subaortic stenosis
ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q24
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- POA Exempt
- Chronic Condition
Q24.4 is a billable ICD-10-CM diagnosis code for congenital subaortic stenosis. 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 major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 61 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
Code Classification
Present on Admission (POA)Billing
Q24.4 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.
- Congenital muscular subaortic stenosis
- Congenital subaortic stenosis
- Congenital subaortic stenosis due to fibromuscular shelf
- Congenital subaortic stenosis due to restrictive ventricular septal defect associated with functionally univentricular heart
- Congenital subaortic stenosis of tunnel type
- Dynamic subaortic stenosis
- Functionally univentricular heart
- Parachute malformation of mitral valve
- Shone complex
- Subaortic stenosis
- Subaortic stenosis and short stature syndrome
- Subaortic stenosis due to common atrioventricular valve
- Subaortic stenosis due to restrictive ventricular septal defect in functionally univentricular heart
- Subneoaortic valve stenosis
- Supramitral left atrial ring
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Q24.4: its own notes plus those printed at Q24 and Chapter 17. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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 Q24.4, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming Q24.4: they are not reported together with it, unless the two conditions are unrelated.
- Q23.0 Congenital stenosis of aortic valvecongenital subaortic stenosis (Q24.4)
Use Additional Code 1
These codes say to use an additional code from the note, and Q24.4 is one of the codes named.
- Q87.88 CTNNB1 syndrome
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Stenosis, stenotic (cicatricial) See Also: Stricture;
subaortic (congenital) Q24.4
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 Q24.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About Q24.4Overview
What is the ICD-10 code for congenital subaortic stenosis?
The ICD-10-CM code for congenital subaortic stenosis is Q24.4 (sometimes written as Q244). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is Q24.4 (Other congenital malformations of heart) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report congenital subaortic stenosis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does Q24.4 group to?
When congenital subaortic stenosis 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 Q24.4 a CC or MCC?
CMS lists Q24.4 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 61 closely related codes in its exclusion list.
Is Q24.4 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 subaortic stenosis on inpatient claims. The code appears in the Congenital malformations of the circulatory system (Q20-Q28) range of the CMS exempt list.
