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ICD10BillableValid for clinical use

ICD-10 Code I33.0: Acute and subacute infective endocarditis

I33.0 is a billable ICD-10 diagnosis code used to classify Acute and subacute infective endocarditis in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the circulatory system (I00-I99).

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the circulatory system (I00-I99).

When is it used?

  • May be used when a clinician documents acute and subacute infective endocarditis in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
9Diseases of the circulatory system (I00-I99)
block
I30-I5AOther forms of heart disease
category
I33Acute and subacute endocarditis
currentI33

Official coding notes

Inclusion terms
  • 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)
Applicable to
  • code (B95-B97) to identify infectious agent
Use additional code
  • code (B95-B97) to identify infectious agent

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

CardiologistGeneral Physician

Coverage-related procedures and services

CPT 93325high
DOPPLER ECHOCARDIOGRAPHY COLOR FLOW VELOCITY MAPPING (LIST SEPARATELY IN ADDITION TO CODES FOR ECHOCARDIOGRAPHY)
Source: CMS coverage guidance
CPT 93320high
DOPPLER ECHOCARDIOGRAPHY, PULSED WAVE AND/OR CONTINUOUS WAVE WITH SPECTRAL DISPLAY (LIST SEPARATELY IN ADDITION TO CODES FOR ECHOCARDIOGRAPHIC IMAGING); COMPLETE
Source: CMS coverage guidance
CPT 93321high
DOPPLER ECHOCARDIOGRAPHY, PULSED WAVE AND/OR CONTINUOUS WAVE WITH SPECTRAL DISPLAY (LIST SEPARATELY IN ADDITION TO CODES FOR ECHOCARDIOGRAPHIC IMAGING); FOLLOW-UP OR LIMITED STUDY (LIST SEPARATELY IN ADDITION TO CODES FOR ECHOCARDIOGRAPHIC IMAGING)
Source: CMS coverage guidance
CPT 93318high
ECHOCARDIOGRAPHY, TRANSESOPHAGEAL (TEE) FOR MONITORING PURPOSES, INCLUDING PROBE PLACEMENT, REAL TIME 2-DIMENSIONAL IMAGE ACQUISITION AND INTERPRETATION LEADING TO ONGOING (CONTINUOUS) ASSESSMENT OF (DYNAMICALLY CHANGING) CARDIAC PUMPING FUNCTION AND TO THERAPEUTIC MEASURES ON AN IMMEDIATE TIME BASIS
Source: CMS coverage guidance
CPT 93314high
ECHOCARDIOGRAPHY, TRANSESOPHAGEAL, REAL-TIME WITH IMAGE DOCUMENTATION (2D) (WITH OR WITHOUT M-MODE RECORDING); IMAGE ACQUISITION, INTERPRETATION AND REPORT ONLY
Source: CMS coverage guidance
CPT 93312high
ECHOCARDIOGRAPHY, TRANSESOPHAGEAL, REAL-TIME WITH IMAGE DOCUMENTATION (2D) (WITH OR WITHOUT M-MODE RECORDING); INCLUDING PROBE PLACEMENT, IMAGE ACQUISITION, INTERPRETATION AND REPORT
Source: CMS coverage guidance

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
I33.0

Common synonyms

Acute and subacute infective endocarditis

Frequently asked questions

Code details

CodeI33.0
SystemICD10
Display nameAcute and subacute infective endocarditis
ChapterDiseases of the circulatory system (I00-I99)
BlockOther forms of heart disease

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)ArthropathyArthropathyDisorder(of)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.