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I51.0

I51.0Cardiac septal defect, acquired

Billable / specific codeICD-10-CM

I51.0 is a billable, specific ICD-10-CM code for cardiac septal defect, acquired. It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • cardiac septal defect as current complication following acute myocardial infarction (I23.1, I23.2)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Acquired septal atrial defect (old)
  • Acquired septal auricular defect (old)
  • Acquired septal ventricular defect (old)

Other codes that can never be billed with I51.0

These codes carry an Excludes1 note pointing at I51.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading I51.0 alone.

  • Q21Congenital malformations of cardiac septa
  • I23.1Atrial septal defect as current complication following acute myocardial infarction
  • I23.2Ventricular septal defect as current complication following acute myocardial infarction

Risk adjustment

I51.0 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

I51.0 is named in 22 Medicare coverage policies 22 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
  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
  • A52868Billing and Coding: Transesophageal Echocardiography (TEE)

How I51.0 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 I51.0.

  • Defect, defectiveseptal NOSacquired(atrial) (auricular) (ventricular) (old)

Related codes at this level

Codes that share I51. If I51.0 is not quite right, the correct code is usually one of these.

Questions about I51.0

Is I51.0 a billable ICD-10-CM code?
Yes. I51.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I51.0 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).
What cannot be coded together with I51.0?
I51.0 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.