DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

I43 diagnosis code · Billable category · FY2027

I43 Cardiomyopathy in diseases classified elsewhere

  • Billable
  • CC
  • HCC 227
  • POA reported

I43 ICD-10 code: a billable diagnosis code in FY2027; the category has no subdivisions.

Where it sits

  1. Chapter 9 Diseases of the circulatory system (I00-I99)
  2. I30-I5A Other forms of heart disease (I30-I5A)
  3. I43 Cardiomyopathy in diseases classified elsewhere
CC / MCC
CC
MS-DRG
314-316, 791, 793
HCC V28
227
POA
Reported
Code Editor
Manifestation
Index entries
45

Instructions

At I43

Excludes1

  • cardiomyopathy (in):
  • coxsackie (virus) (B33.24) B33.24
  • diphtheria (A36.81) A36.81
  • sarcoidosis (D86.85) D86.85
  • tuberculosis (A18.84) A18.84

Code first

  • underlying disease, such as:
  • amyloidosis (E85.-) E85
  • glycogen storage disease (E74.0-) E74.0
  • gout (M10.0-) M10.0
  • thyrotoxicosis (E05.0-E05.9-) E05.0 E05.9

Notes that also apply

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

Index entries

  • Cardiomegalia glycogenica diffusa → E74.02 [I43]
  • Amyloid heart (disease) → E85.4 [I43]
  • Cardiomyopathy (familial) (idiopathic)thyrotoxic → E05.90 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)thyrotoxic → E05.90 [I43]
  • Thyrotoxicheart disease or failure → E05.90 [I43]
  • Thyrotoxicosis (recurrent)heart → E05.90 [I43]
  • Cardiomyopathy (familial) (idiopathic)nutritional → E63.9 [I43]
  • Cardiomegalyglycogen → E74.02 [I43]
  • Cardiomyopathy (familial) (idiopathic)glycogen storage → E74.02 [I43]
  • Glycogenosis (diffuse) (generalized)cardiac → E74.02 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)glycogen storage → E74.02 [I43]
  • Amyloidosis (generalized) (primary)heart → E85.4 [I43]
  • Cardiomyopathy (familial) (idiopathic)amyloid → E85.4 [I43]
  • Cardiomyopathy (familial) (idiopathic)metabolic → E88.9 [I43]
  • Cardiomyopathy (familial) (idiopathic)metabolicthyrotoxic → E05.90 [I43]
  • Disease, diseasedheart (organic)hyperthyroid → E05.90 [I43]
  • Disease, diseasedheart (organic)thyrotoxic → E05.90 [I43]
  • Disease, diseasedthyroid (gland)heart → E05.90 [I43]
  • Failure, failedNote: heart failure stages A, B, C, and D are based on the American College of Cardiology and American Heart Association stages of heart failure, which complement and should not be confused with the New York Heart Association Classification of Heart Failure, into Class I, Class II, Class III, and Class IVthyrotoxic → E05.90 [I43]
  • Thyrotoxicosis (recurrent)heartfailure → E05.90 [I43]
  • Cardiomyopathy (familial) (idiopathic)thyrotoxicwith thyroid storm → E05.91 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)thyrotoxicwith storm → E05.91 [I43]
  • Thyrotoxicheart disease or failurewith thyroid storm → E05.91 [I43]
  • Thyrotoxicosis (recurrent)heartwith thyroid storm → E05.91 [I43]
  • Cardiomyopathy (familial) (idiopathic)due tocardiac glycogenosis → E74.02 [I43]
  • Disease, diseasedglycogen storageheart → E74.02 [I43]
  • Disease, diseasedglycogen storagemyocardium → E74.02 [I43]
  • Disease, diseasedheart (organic)glycogen storage → E74.02 [I43]
  • Infiltrate, infiltrationcardiacglycogenic → E74.02 [I43]
  • Infiltrate, infiltrationheart, cardiacglycogenic → E74.02 [I43]
  • Infiltrate, infiltrationmyocardium, myocardialglycogenic → E74.02 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)in (due to)cardiac glycogenosis → E74.02 [I43]
  • Cardiomyopathy (familial) (idiopathic)amyloidtransthyretin-related (ATTR) familial → E85.4 [I43]
  • Degeneration, degenerativeheartamyloid → E85.4 [I43]
  • Disease, diseasedheart (organic)amyloid → E85.4 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)in (due to)Friedreich's ataxia → G11.11 [I43]
  • Cardiomyopathy (familial) (idiopathic)due toprogressive muscular dystrophy → G71.09 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)in (due to)progressive muscular dystrophy → G71.09 [I43]
  • Cardiomyopathy (familial) (idiopathic)due tomyotonia atrophica → G71.11 [I43]
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)in (due to)myotonia atrophica → G71.11 [I43]

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

NCHS Alphabetic Index. Index first, then the Tabular List.

Medicare grouping and edits

CMS files for I43
CC / MCCCC
PDX exclusion list0819 (117 codes)
Appendix BMDC 05 Diseases and Disorders of the Circulatory System, MS-DRG 314-316 (Other Circulatory System Diagnoses with MCC…); MDC 15 Newborns and Other Neonates with Conditions Originating in Perinatal Period, MS-DRG 791 (Prematurity with Major Problems…); MDC 15 Newborns and Other Neonates with Conditions Originating in Perinatal Period, MS-DRG 793 (Full Term Neonate with Major Problems…)
Code EditorManifestation code: not allowed as principal diagnosis
POAReported
HCC V28HCC 227 Cardiomyopathy/Myocarditis

CC as a secondary diagnosis, not when the principal diagnosis is on its PDX exclusion list.

CMS: MS-DRG v44 (Appendix B, C), MCE v44, POA list FY2027, 2027 Initial ICD-10-CM Mappings. What the rows mean.

Hierarchy