2026 ICD-10-CM Diagnosis Code I51.5Myocardial degeneration
ICD-10-CM Codes›I00–I99›I30-I5A›I51
- Billable — Valid for Submission
- Chronic Condition
I51.5 is a billable ICD-10-CM diagnosis code for myocardial degeneration. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. Coders also document this condition as fatty degeneration of heart. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined heart disease.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Fatty degeneration of heart
- Myocardial degeneration
- Myocardial disease
- Myocardial dysfunction
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Fatty degeneration of heart or myocardium
- Myocardial disease
- Senile degeneration of heart or myocardium
Type 1 Excludes
- myocardial degeneration due to hypertension I11
- myocardial degeneration due to hypertension and chronic kidney disease I13
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Cardiomalacia - I51.5
- Cardiomyoliposis - I51.5
- Disease, diseased - See Also: Syndrome;
- myocardium, myocardial - See Also: Degeneration, myocardial; - I51.5
- Myocytolysis - I51.5
- Stricture - See Also: Stenosis;
- myocardium, myocardial - I51.5
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Cardiomalacia
- Cardiomyoliposis
- Degeneration, degenerative
- myocardial, myocardium (fatty) (hyaline) (senile)
- Disease, diseased
- myocardium, myocardial
- Myocytolysis
- Stricture
- myocardium, myocardial
- Syndrome
- Beau's
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Myocardial Degeneration
degeneration of myocardial tissue.
Patient EducationClinical
Cardiomyopathy
Cardiomyopathy is the name for diseases of the heart muscle. These diseases enlarge your heart muscle or make it thicker and more rigid than normal. In rare cases, scar tissue replaces the muscle tissue.
Read the full article at MedlinePlus
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Convert I51.5 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I51.5Overview
Is I51.5 (Complications and ill-defined descriptions of heart disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report myocardial degeneration on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I51.5 group to?
When myocardial degeneration is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of I51.5?
Under the General Equivalence Mappings, myocardial degeneration converts to ICD-9-CM 429.1 (myocardial degeneration). The mapping is a direct match.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
