I43 Cardiomyopathy in diseases classified elsewhere

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Excludes1 (never code together)

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

Code first

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

Applies from I43 Cardiomyopathy in diseases classified elsewhere

Excludes1 (never code together)

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

Code first

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

Risk adjustment (HCC)

• CMS-HCC V28: HCC 227 — Cardiomyopathy/Myocarditis
• CMS-HCC V22: HCC 85 — Congestive Heart Failure
• RxHCC V08: HCC 186 — Heart Failure
• ESRD V24: HCC 85

MS-DRG index

Defines the logic of DRG(s) 314-316 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 425.8 Cardiomyopathy in other diseases classified elsewhere (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Manifestation codes as principal diagnosis: Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and are not allowed as principal diagnosis.

Code annotations containing back-references to I43

Back-references to I43

• Use Additional: M1A Chronic gout ("Cardiomyopathy in diseases classified elsewhere (I43)")
• Use Additional: M10 Gout ("Cardiomyopathy in diseases classified elsewhere (I43)")

Back-references to I43

• Use Additional: M1A Chronic gout ("Cardiomyopathy in diseases classified elsewhere (I43)")
• Use Additional: M10 Gout ("Cardiomyopathy in diseases classified elsewhere (I43)")

Diagnosis Index entries for I43

• Amyloid heart (disease)
• Amyloidosis (generalized) (primary) › heart
• Cardiomegalia glycogenica diffusa
• Cardiomegaly › glycogen
• Cardiomyopathy (familial) (idiopathic) › amyloid
• Cardiomyopathy (familial) (idiopathic) › amyloid › transthyretin-related (ATTR) familial
• Cardiomyopathy (familial) (idiopathic) › due to › cardiac glycogenosis
• Cardiomyopathy (familial) (idiopathic) › due to › myotonia atrophica
• Cardiomyopathy (familial) (idiopathic) › due to › progressive muscular dystrophy
• Cardiomyopathy (familial) (idiopathic) › glycogen storage
• Cardiomyopathy (familial) (idiopathic) › metabolic
• Cardiomyopathy (familial) (idiopathic) › metabolic › thyrotoxic
• Cardiomyopathy (familial) (idiopathic) › metabolic › thyrotoxic › with thyroid storm
• Cardiomyopathy (familial) (idiopathic) › nutritional
• Cardiomyopathy (familial) (idiopathic) › thyrotoxic
• Cardiomyopathy (familial) (idiopathic) › thyrotoxic › with thyroid storm
• Degeneration, degenerative › heart › amyloid
• Disease, diseased › glycogen storage › heart
• Disease, diseased › glycogen storage › myocardium
• Disease, diseased › heart (organic) › amyloid
• Disease, diseased › heart (organic) › glycogen storage
• Disease, diseased › heart (organic) › hyperthyroid
• Disease, diseased › heart (organic) › hyperthyroid › with thyroid storm
• Disease, diseased › heart (organic) › thyrotoxic
• Disease, diseased › heart (organic) › thyrotoxic › with thyroid storm
• Disease, diseased › thyroid (gland) › heart
• Disease, diseased › thyroid (gland) › heart › with thyroid storm
• Failure, failed › Note: 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 IV › thyrotoxic
• Failure, failed › Note: 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 IV › thyrotoxic › with › thyroid storm
• Glycogenosis (diffuse) (generalized) › cardiac
• Infiltrate, infiltration › cardiac › glycogenic
• Infiltrate, infiltration › heart, cardiac › glycogenic
• Infiltrate, infiltration › myocardium, myocardial › glycogenic
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › glycogen storage
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › in (due to) › cardiac glycogenosis
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › in (due to) › Friedreich's ataxia
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › in (due to) › myotonia atrophica
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › in (due to) › progressive muscular dystrophy
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › thyrotoxic
• Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › thyrotoxic › with storm
• Thyrotoxic › heart disease or failure
• Thyrotoxic › heart disease or failure › with thyroid storm
• Thyrotoxicosis (recurrent) › heart
• Thyrotoxicosis (recurrent) › heart › with thyroid storm
• Thyrotoxicosis (recurrent) › heart › failure

Nearby codes

• I43 Cardiomyopathy in diseases classified elsewhere (this code)