10ICD Code Hub

Q21.8

Billable code

Other congenital malformations of cardiac septa

The ICD-10 code for other congenital malformations of cardiac septa is Q21.8.

Clinical notes

Code also

Two codes may be needed to fully describe a condition, but unlike Code First/Use Additional Code, the sequencing order is not mandated by convention.

  • , if applicable:
  • Eisenmenger's complex (I27.83)
  • Eisenmenger's syndrome (I27.83)

Also known as

Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.

  • Eisenmenger's defect
  • Pentalogy of Fallot

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

Related codes in this category

ICD-9-CM equivalent

Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.

View full ICD-10 → ICD-9 crosswalk →

Associated MS-DRGs

Q21.8 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.