I42.2
Other hypertrophic cardiomyopathy
I42.2 (also written I422) is a billable ICD-10-CM diagnosis code for other hypertrophic cardiomyopathy. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 13 codes in category I42 (Cardiomyopathy). The Alphabetic Index lists it under 2 entries. Its coding notes include a Code first instruction and 13 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (10 notes)
- 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.-)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Cardiac and Circulatory clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 117 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CIncludes
Further defines or gives examples of the content of the category.
- myocardiopathy
Inclusion terms
Conditions classified to this code.
- Nonobstructive hypertrophic cardiomyopathy
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 2 entries