2020 ICD-10-CM Diagnosis Code I33.9

Acute and subacute endocarditis, unspecified

    2016 2017 2018 2019 2020 Billable/Specific Code
  • I33.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2020 edition of ICD-10-CM I33.9 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of I33.9 - other international versions of ICD-10 I33.9 may differ.
Applicable To
  • Acute endocarditis NOS
  • Acute myoendocarditis NOS
  • Acute periendocarditis NOS
  • Subacute endocarditis NOS
  • Subacute myoendocarditis NOS
  • Subacute periendocarditis NOS
The following code(s) above I33.9 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to I33.9:
  • I00-I99
    2020 ICD-10-CM Range I00-I99

    Diseases of the circulatory system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    • systemic connective tissue disorders (M30-M36)
    • transient cerebral ischemic attacks and related syndromes (G45.-)
    Diseases of the circulatory system
  • I33
    ICD-10-CM Diagnosis Code I33

    Acute and subacute endocarditis

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • acute rheumatic endocarditis (I01.1)
    • endocarditis NOS (I38)
    Acute and subacute endocarditis
Approximate Synonyms
  • Acute endocarditis
  • Acute endocarditis (infection of heart valve)
  • Acute nonbacterial endocarditis
  • Endocarditis (infection of heart valve), subacute
  • Subacute endocarditis
  • Subacute endocarditis (infection of heart valve)
Clinical Information
  • Acute inflammation of the endocardium. Bacteria is the usual etiologic agent, and the distinction between "acute" and "subacute" has traditionally been made based on the pathogenic organism and clinical presentation.
ICD-10-CM I33.9 is grouped within Diagnostic Related Group(s) (MS-DRG v37.0):
  • 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 I33.9 to ICD-9-CM

Code 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

Diagnosis Index entries containing back-references to I33.9:
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular) I38
    ICD-10-CM Diagnosis Code I38

    Endocarditis, valve unspecified

      2016 2017 2018 2019 2020 Billable/Specific Code
    Includes
    • endocarditis (chronic) NOS
    • valvular incompetence NOS
    • valvular insufficiency NOS
    • valvular regurgitation NOS
    • valvular stenosis NOS
    • valvulitis (chronic) NOS
    Type 1 Excludes
    • congenital insufficiency of cardiac valve NOS (Q24.8)
    • congenital stenosis of cardiac valve NOS (Q24.8)
    • endocardial fibroelastosis (I42.4)
    • endocarditis specified as rheumatic (I09.1)
    • acute or subacute I33.9
    • aortic (heart) (nonrheumatic) (valve) I35.8
      ICD-10-CM Diagnosis Code I35.8

      Other nonrheumatic aortic valve disorders

        2016 2017 2018 2019 2020 Billable/Specific Code
      • acute or subacute I33.9
    • mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea) I05.9
      ICD-10-CM Diagnosis Code I05.9

      Rheumatic mitral valve disease, unspecified

        2016 2017 2018 2019 2020 Billable/Specific Code
      Applicable To
      • Rheumatic mitral (valve) disorder (chronic) NOS
      • nonrheumatic I34.8
        ICD-10-CM Diagnosis Code I34.8

        Other nonrheumatic mitral valve disorders

          2016 2017 2018 2019 2020 Billable/Specific Code
        • acute or subacute I33.9
    • pulmonary (chronic) (heart) (valve) I37.8
      ICD-10-CM Diagnosis Code I37.8

      Other nonrheumatic pulmonary valve disorders

        2016 2017 2018 2019 2020 Billable/Specific Code
    • tricuspid (chronic) (heart) (inactive) (rheumatic) (valve) (with chorea) I07.9
      ICD-10-CM Diagnosis Code I07.9

      Rheumatic tricuspid valve disease, unspecified

        2016 2017 2018 2019 2020 Billable/Specific Code
      Applicable To
      • Rheumatic tricuspid valve disorder NOS
      • nonrheumatic I36.8
        ICD-10-CM Diagnosis Code I36.8

        Other nonrheumatic tricuspid valve disorders

          2016 2017 2018 2019 2020 Billable/Specific Code
        • acute or subacute I33.9
    • toxic I33.9

ICD-10-CM Codes Adjacent To I33.9
I31.0 Chronic adhesive pericarditis
I31.1 Chronic constrictive pericarditis
I31.2 Hemopericardium, not elsewhere classified
I31.3 Pericardial effusion (noninflammatory)
I31.4 Cardiac tamponade
I31.8 Other specified diseases of pericardium
I31.9 Disease of pericardium, unspecified
I32 Pericarditis in diseases classified elsewhere
I33 Acute and subacute endocarditis
I33.0 Acute and subacute infective endocarditis
I33.9 Acute and subacute endocarditis, unspecified
I34 Nonrheumatic mitral valve disorders
I34.0 Nonrheumatic mitral (valve) insufficiency
I34.1 Nonrheumatic mitral (valve) prolapse
I34.2 Nonrheumatic mitral (valve) stenosis
I34.8 Other nonrheumatic mitral valve disorders
I34.9 Nonrheumatic mitral valve disorder, unspecified
I35 Nonrheumatic aortic valve disorders
I35.0 Nonrheumatic aortic (valve) stenosis
I35.1 Nonrheumatic aortic (valve) insufficiency
I35.2 Nonrheumatic aortic (valve) stenosis with insufficiency

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.