DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

I51 Complications and ill-defined descriptions of heart disease

  • Header · not billable

I51 is not billable. The category heads 10 billable codes in FY2027, grouped under 9 subdivisions.

Index → code

Where it sits

  1. Chapter 9 Diseases of the circulatory system (I00-I99)
  2. I30-I5A Other forms of heart disease (I30-I5A)
  3. I51 Complications and ill-defined descriptions of heart disease
Billable codes
10
Subdivisions
9
CC / MCC codes
2 / 2
HCC V28 codes
4
New FY2027
0
Index entries
60

Codes in I51

  1. I51.0
    Cardiac septal defect, acquired
    BillableCC
    Inclusion terms 3, Excludes1 1

    Inclusion terms

    • Acquired septal atrial defect (old)
    • Acquired septal auricular defect (old)
    • Acquired septal ventricular defect (old)

    Excludes1

    • cardiac septal defect as current complication following acute myocardial infarction (I23.1, I23.2) I23.1 I23.2
  2. I51.1
    Rupture of chordae tendineae, not elsewhere classified
    BillableMCC229
    Excludes1 1

    Excludes1

    • rupture of chordae tendineae as current complication following acute myocardial infarction (I23.4) I23.4
  3. I51.2
    Rupture of papillary muscle, not elsewhere classified
    BillableMCC229
    Excludes1 1

    Excludes1

    • rupture of papillary muscle as current complication following acute myocardial infarction (I23.5) I23.5
  4. I51.3
    Intracardiac thrombosis, not elsewhere classified
    Billable
    Inclusion terms 5, Excludes1 1

    Inclusion terms

    • Apical thrombosis (old)
    • Atrial thrombosis (old)
    • Auricular thrombosis (old)
    • Mural thrombosis (old)
    • Ventricular thrombosis (old)

    Excludes1

    • intracardiac thrombosis as current complication following acute myocardial infarction (I23.6) I23.6
  5. I51.4
    Myocarditis, unspecified
    Billable227
    Inclusion terms 3, Excludes1 1

    Inclusion terms

    • Chronic (interstitial) myocarditis
    • Myocardial fibrosis
    • Myocarditis NOS

    Excludes1

    • acute or subacute myocarditis (I40.-) I40
  6. I51.5
    Myocardial degeneration
    Billable227
    Inclusion terms 3, Excludes1 2

    Inclusion terms

    • Fatty degeneration of heart or myocardium
    • Myocardial disease
    • Senile degeneration of heart or myocardium

    Excludes1

    • myocardial degeneration due to hypertension (I11.-) I11
    • myocardial degeneration due to hypertension and chronic kidney disease (I13.-) I13
  7. I51.7
    Cardiomegaly
    Billable
    Inclusion terms 3, Excludes1 2

    Inclusion terms

    • Cardiac dilatation
    • Cardiac hypertrophy
    • Ventricular dilatation

    Excludes1

    • cardiomegaly due to hypertension (I11.-) I11
    • cardiomegaly due to hypertension and chronic kidney disease (I13.-) I13
  8. I51.8
    Other ill-defined heart diseases
    Header
  9. I51.81
    Takotsubo syndrome
    BillableCC
    Inclusion terms 4

    Inclusion terms

    • Reversible left ventricular dysfunction following sudden emotional stress
    • Stress induced cardiomyopathy
    • Takotsubo cardiomyopathy
    • Transient left ventricular apical ballooning syndrome
  10. I51.89
    Other ill-defined heart diseases
    Billable
    Inclusion terms 2

    Inclusion terms

    • Carditis (acute)(chronic)
    • Pancarditis (acute)(chronic)
  11. I51.9
    Heart disease, unspecified
    Billable

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column.

Instructions

At I51

Excludes2

  • heart disease specified as rheumatic (I00-I09) I00 I09

Notes that also apply

Chapter 9 instructions (Excludes2 10): printed on the chapter 9 page.

Index entries

  • Acardiotrophia → I51.4
  • Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile) → I51.4
  • Cardiomalacia → I51.5
  • Cardiomyoliposis → I51.5
  • Myocytolysis → I51.5
  • Preponderance, left or right ventricular → I51.7
  • Carditis (acute) (bacterial) (chronic) (subacute) → I51.89
  • Pancarditis (acute) (chronic) → I51.89
  • Cardiopathy → I51.9
  • Lacerationchordae tendinae NEC → I51.1
  • Rupture, rupturedchordae tendineae NEC → I51.1
  • Rupture, rupturedpapillary muscle NEC → I51.2
  • Thrombosis, thrombotic (bland) (multiple) (progressive) (silent) (vessel)intracardiac NEC (apical) (atrial) (auricular) (ventricular) (old) → I51.3
  • Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification)myocarditis → I51.4
  • Degeneration, degenerativemyocardial, myocardium (fatty) (hyaline) (senile) → I51.5
  • Disease, diseasedmyocardium, myocardial → I51.5
  • Stricturemyocardium, myocardial → I51.5
  • SyndromeBeau's → I51.5
  • Athlete'sheart → I51.7
  • Cardiomegalyidiopathic → I51.7
  • Hypertrophy, hypertrophiccardiac (chronic) (idiopathic) → I51.7
  • Cardiomyopathy (familial) (idiopathic)stress induced → I51.81
  • Cardiomyopathy (familial) (idiopathic)takotsubo → I51.81
  • Dysfunctionleft ventricular, following sudden emotional stress → I51.81
  • Syndromeapical ballooning (transient left ventricular) → I51.81
  • Syndrometakotsubo → I51.81
  • Syndrometransient left ventricular apical ballooning → I51.81
  • Asynergia, asynergyventricular → I51.89
  • Disorder (of)cardiac, functional → I51.89
  • Dysfunctionheart → I51.89
  • Dysfunctionpapillary muscle → I51.89
  • Hemorrhage, hemorrhagic (concealed)heart → I51.89
  • Hyperkinesia, hyperkinetic (disease) (reaction) (syndrome) (childhood) (adolescence)heart → I51.89
  • Complication(s) (from) (of)heart → I51.9
  • Disease, diseasedheart (organic) → I51.9
  • Dysfunctionventricular → I51.9
  • Lesion(s) (nontraumatic)cardiac → I51.9
  • Morbuscordis → I51.9
  • Defect, defectiveseptal (heart) NOSacquired (atrial) (auricular) (ventricular) (old) → I51.0
  • Clot (blood)heartnot resulting in infarction → I51.3

20 more, longer entries are not listed; the search box finds them by word.

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