2025 ICD-10-CM Diagnosis Code I33.0

Acute and subacute infective endocarditis

• I33.0 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• The 2025 edition of ICD-10-CM I33.0 became effective on October 1, 2024.
• This is the American ICD-10-CM version of I33.0 – other international versions of ICD-10 I33.0 may differ.

Applicable To

• Bacterial endocarditis (acute) (subacute)
• Infective endocarditis (acute) (subacute) NOS
• Endocarditis lenta (acute) (subacute)
• Malignant endocarditis (acute) (subacute)
• Purulent endocarditis (acute) (subacute)
• Septic endocarditis (acute) (subacute)
• Ulcerative endocarditis (acute) (subacute)
• Vegetative endocarditis (acute) (subacute)

Use Additional

• code (B95-B97 ) to identify infectious agent

The following code(s) above I33.0 contain annotation back-references

 that may be applicable to I33.0:

• I00-I99  Diseases of the circulatory system
• I33  Acute and subacute endocarditis

Approximate Synonyms

• Acute or subacute mycotic aneurysm
• Bacterial endocarditis
• Bacterial endocarditis (infection of heart valve)
• Fungal endocarditis
• Histoplasma capsulatum with endocarditis
• Histoplasmosis endocarditis
• Infection and inflammatory reaction due to cardiac valve prosthesis
• Infection of prosthetic valve
• Mycotic aneurysm due to bacterial endocarditis
• Mycotic endocarditis

ICD-10-CM I33.0 is grouped within Diagnostic Related Group(s) (MS-DRG v42.0):

• 288 Acute and subacute endocarditis with mcc
• 289 Acute and subacute endocarditis with cc
• 290 Acute and subacute endocarditis without cc/mcc
• 791 Prematurity with major problems
• 793 Full term neonate with major problems
• 974 Hiv with major related condition with mcc
• 975 Hiv with major related condition with cc
• 976 Hiv with major related condition without cc/mcc

Convert I33.0 to ICD-9-CMCode History

• 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
• 2017 (effective 10/1/2016): No change
• 2018 (effective 10/1/2017): No change
• 2019 (effective 10/1/2018): No change
• 2020 (effective 10/1/2019): No change
• 2021 (effective 10/1/2020): No change
• 2022 (effective 10/1/2021): No change
• 2023 (effective 10/1/2022): No change
• 2024 (effective 10/1/2023): No change
• 2025 (effective 10/1/2024): No change

Code annotations containing back-references to I33.0:

• Code First: I76, M02

Diagnosis Index entries containing back-references to I33.0:

• Aneurysm (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular) I72.9
  • infectiveI72.9
    • endocardial I33.0 (any valve)
  • mycoticI72.9
    • endocardial I33.0 (any valve)
  • endocardial, infective I33.0 (any valve)
• ArthropathyM12.9 – see also Arthritis
  • in (due to)
    • infective endocarditis I33.0
  • reactiveM02.9
    • in (due to)
      • infective endocarditis I33.0
• Disorder (of) – see also Disease
  • glomerular (in) N05.9
    • subacute bacterial endocarditis I33.0
• Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular) I38
  • acute or subacuteI33.9
    • infective I33.0
  • due to
    • Serratia marcescens I33.0
  • mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea) I05.9
    • active or acuteI01.1
      • bacterial I33.0
  • bacterial I33.0 (acute) (any valve) (subacute)
  • constrictive I33.0
  • infectious or infective I33.0 (acute) (any valve) (subacute)
  • lenta I33.0 (acute) (any valve) (subacute)
  • malignant I33.0 (acute) (any valve) (subacute)
  • mycotic I33.0 (acute) (any valve) (subacute)
  • pneumococcal I33.0 (acute) (any valve) (subacute)
  • purulent I33.0 (acute) (any valve) (subacute)
  • septic I33.0 (acute) (any valve) (subacute)
  • streptococcal I33.0 (acute) (any valve) (subacute)
  • suppurative I33.0 (acute) (any valve) (subacute)
  • ulcerative I33.0 (acute) (any valve) (subacute)
  • vegetative I33.0 (acute) (any valve) (subacute)
• GlomerulonephritisN05.9 – see also Nephritis
  • in (due to)
    • subacute bacterial endocarditis I33.0
• Infection, infected, infective (opportunistic) B99.9
  • endocardium I33.0
• Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) N05.9
  • due to
    • subacute bacterial endocarditis I33.0
• Node(s) – see also Nodule
  • Osler’s I33.0
• Osler’s nodes I33.0
• SBE I33.0 (subacute bacterial endocarditis)
• Ulcer, ulcerated, ulcerating, ulceration, ulcerative
  • valve, heart I33.0
• Vegetation, vegetative
  • endocarditis I33.0 (acute) (any valve) (subacute)
  • heart I33.0 (mycotic) (valve)