Chapter 9

I00–I99: Diseases of the Circulatory System

Diseases of the Circulatory System diagnostic classification updated for 2026.

Chapter Instructions

Excludes2(Not included here. Code separately if applicable.)
  • 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.-)
Internal Codes
  • I00

    Rheumatic fever without heart involvement

  • I01.0

    Acute rheumatic pericarditis

  • I01.1

    Acute rheumatic endocarditis

  • I01.2

    Acute rheumatic myocarditis

  • I01.8

    Other acute rheumatic heart disease

  • I01.9

    Acute rheumatic heart disease, unspecified

  • I02.0

    Rheumatic chorea with heart involvement

  • I02.9

    Rheumatic chorea without heart involvement

  • I05.0

    Rheumatic mitral stenosis

  • I05.1

    Rheumatic mitral insufficiency

  • I05.2

    Rheumatic mitral stenosis with insufficiency

  • I05.8

    Other rheumatic mitral valve diseases

  • I05.9

    Rheumatic mitral valve disease, unspecified

  • I06.0

    Rheumatic aortic stenosis

  • I06.1

    Rheumatic aortic insufficiency

  • I06.2

    Rheumatic aortic stenosis with insufficiency

  • I06.8

    Other rheumatic aortic valve diseases

  • I06.9

    Rheumatic aortic valve disease, unspecified

  • I07.0

    Rheumatic tricuspid stenosis

  • I07.1

    Rheumatic tricuspid insufficiency

  • I07.2

    Rheumatic tricuspid stenosis and insufficiency

  • I07.8

    Other rheumatic tricuspid valve diseases

  • I07.9

    Rheumatic tricuspid valve disease, unspecified

  • I08.0

    Rheumatic disorders of both mitral and aortic valves

  • I08.1

    Rheumatic disorders of both mitral and tricuspid valves

  • I08.2

    Rheumatic disorders of both aortic and tricuspid valves

  • I08.3

    Combined rheumatic disorders of mitral, aortic and tricuspid valves

  • I08.8

    Other rheumatic multiple valve diseases

  • I08.9

    Rheumatic multiple valve disease, unspecified

  • I09.0

    Rheumatic myocarditis

  • I09.1

    Rheumatic diseases of endocardium, valve unspecified

  • I09.2

    Chronic rheumatic pericarditis

  • I09.81

    Rheumatic heart failure

  • I09.89

    Other specified rheumatic heart diseases

  • I09.9

    Rheumatic heart disease, unspecified

  • I10

    Essential (primary) hypertension

  • I11.0

    Hypertensive heart disease with heart failure

  • I11.9

    Hypertensive heart disease without heart failure

  • I12.0

    Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease

  • I12.9

    Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease

  • I13.0

    Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease

  • I13.10

    Hypertensive heart and chronic kidney disease without heart failure, with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease

  • I13.11

    Hypertensive heart and chronic kidney disease without heart failure, with stage 5 chronic kidney disease, or end stage renal disease

  • I13.2

    Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease

  • I15.0

    Renovascular hypertension

  • I15.1

    Hypertension secondary to other renal disorders

  • I15.2

    Hypertension secondary to endocrine disorders

  • I15.8

    Other secondary hypertension

  • I15.9

    Secondary hypertension, unspecified

  • I16.0

    Hypertensive urgency

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