2027 ICD-10-CM Diagnosis Code I42.89Other cardiomyopathies not elsewhere classified
ICD-10-CM Codes›I00–I99›I30-I5A›I42
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- New 2027 Code
I42.89 is a billable ICD-10-CM diagnosis code for other cardiomyopathies not elsewhere classified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 314 through 316. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 117 closely related codes.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cardiomyopathy
- Coenzyme Q10 deficiency
- Disorder of myocardium associated with rejection of cardiac transplant
- Dystrophic cardiomyopathy
- Fatal infantile mitochondrial cardiomyopathy
- Histiocytoid mitochondrial cardiomyopathy
- Histiocytoid mitochondrial cardiomyopathy due to cytochrome aa3 deficiency
- Hypertrophic mitochondrial cardiomyopathy
- Infiltrative cardiomyopathy
- Inflammatory cardiomyopathy
- Left ventricular myocardial noncompaction cardiomyopathy
- Lethal left ventricular non-compaction, seizures, hypotonia, cataract, developmental delay syndrome
- Macrocephaly, intellectual disability, left ventricular non compaction syndrome
- Maternally inherited mitochondrial cardiomyopathy
- Maternally inherited mitochondrial cardiomyopathy and myopathy
- Mitochondrial cardiomyopathy
- Myocardial degeneration
- Neonatal encephalomyopathy, cardiomyopathy, respiratory distress syndrome
- Nonobstructive cardiomyopathy
- Post-myocarditic cardiomyopathy
- Primary cardiomyopathy
- Right ventricular myocardial noncompaction cardiomyopathy
- TMEM70 related mitochondrial encephalo-cardio-myopathy
- Valvular cardiomyopathy
- Ventricular myocardial noncompaction cardiomyopathy
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I42.89: its own notes plus those printed at I42 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- 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.-)
Code First
The underlying condition named in the note is sequenced before this code.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name I42.89, its category, or a range that includes it.
Applicable To 1
These notes mention I42.89.
Code First 1
These codes say to code first a condition named in the note, and I42.89 is one of the conditions named.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
cardiomyopathy I42.89
Cardiomyopathy (familial) (idiopathic) I42.9
newborn I42.89
non-ischemic See Also: by cause; I42.89
obscure of Africa I42.89
specified NEC I42.89
Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) See Also: Cardiomyopathy; I42.9
obscure (African) I42.89
Syndrome See Also: Disease;
South African cardiomyopathy I42.89
Clinical InformationClinical
Cardiomyopathies
a group of diseases in which the dominant feature is the involvement of the cardiac muscle itself. cardiomyopathies are classified according to their predominant pathophysiological features (dilated cardiomyopathy; hypertrophic cardiomyopathy; restrictive cardiomyopathy) or their etiological/pathological factors (cardiomyopathy, alcoholic; endocardial fibroelastosis).
Code History & ChangesHistory
New Code I42.89 was added to the ICD-10-CM code set for FY 2027, effective October 1, 2026.
Replacement I42.89 replaces the following previously assigned code(s):
- I42.8 - Other cardiomyopathies
Questions About I42.89Overview
What is the ICD-10 code for other cardiomyopathies not elsewhere classified?
The ICD-10-CM code for other cardiomyopathies not elsewhere classified is I42.89 (sometimes written as I4289). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I42.89 (Other cardiomyopathies) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other cardiomyopathies not elsewhere classified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I42.89 group to?
When other cardiomyopathies not elsewhere classified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 316, 315, with relative weights from 0.6678 to 2.0871 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I42.89 a CC or MCC?
CMS lists I42.89 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 117 closely related codes in its exclusion list.
