Q23.4 — Hypoplastic left heart syndrome
Q23.4 is a billable, specific ICD-10-CM code for hypoplastic left heart syndrome. It is valid for submission on a claim.
Other codes that can never be billed with Q23.4
These codes carry an Excludes1 note pointing at Q23.4. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Q23.4 alone.
Risk adjustment
Q23.4 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
Q23.4 is named in 24 Medicare coverage policies — 24 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
How Q23.4 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Q23.4.
- Hypoplasia, hypoplastic›left heart syndrome
- Syndrome›hypoplastic left-heart
- Atresia, atretic›aortic›congenital with hypoplasia of ascending aorta and defective development of left ventricle(with mitral stenosis)
- Atresia, atretic›aortic›in hypoplastic left heart syndrome
- Atresia, atretic›mitral valve›in hypoplastic left heart syndrome
- Hypoplasia, hypoplastic›aorta, aortic›ascending, in hypoplastic left heart syndrome
- Development›defective, congenital›left ventricle›in hypoplastic left heart syndrome
- Hypoplasia, hypoplastic›aorta, aortic›valve›in hypoplastic left heart syndrome
Related codes at this level
Codes that share Q23. If Q23.4 is not quite right, the correct code is usually one of these.
Questions about Q23.4
- Is Q23.4 a billable ICD-10-CM code?
- Yes. Q23.4 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does Q23.4 sit in the tabular list?
- Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Congenital malformations of the circulatory system (Q20-Q28).