I33.9

ICD-10Billable

Acute and subacute endocarditis, unspecified

Official ICD-10-CM descriptor (FY2026)

Acute and subacute endocarditis, unspecified

I33.9 is valid for submission on a claim — CMS flags it as a billable, specific code.

Inclusion terms

  • Acute endocarditis NOS
  • Acute myoendocarditis NOS
  • Acute periendocarditis NOS
  • Subacute endocarditis NOS
  • Subacute myoendocarditis NOS
  • Subacute periendocarditis NOS

Related codes in I33

Where this code sits

Parent code
I33

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Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.

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