ICD-10-CM 2027 diagnosis code
I42.2Other hypertrophic cardiomyopathy
I42.2 is a valid, billable ICD-10-CM code for other hypertrophic cardiomyopathy. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Hypertrophic nonobstructive cardiomyopathy.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About I42.2
I42.2 is the ICD-10-CM diagnosis code for other hypertrophic cardiomyopathy. It belongs to category I42 (cardiomyopathy), block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within I42, choose I42.2 (Other hypertrophic cardiomyopathy) only when documentation doesn't support a more specific option: dilated cardiomyopathy (I42.0), obstructive hypertrophic cardiomyopathy (I42.1), Endomyocardial (eosinophilic) disease (I42.3), endocardial fibroelastosis (I42.4), other restrictive cardiomyopathy (I42.5), alcoholic cardiomyopathy (I42.6), due to drug and external agent (I42.7), other cardiomyopathies (I42.8) and 1 more.
Code first: pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 314 (Other Circulatory System Diagnoses with MCC, relative weight 2.0873), DRG 315 (Other Circulatory System Diagnoses with CC, relative weight 0.9508) and DRG 316 (Other Circulatory System Diagnoses without CC/MCC, relative weight 0.6677), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 425.18 (other hypertrophic cardiomyopathy).
Coding notes
- Nonobstructive hypertrophic cardiomyopathy
Notes that apply from higher levels
Instructions written at a parent level also apply to I42.2.
› From I42 Cardiomyopathy
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to I42.2.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 05 · Diseases and Disorders of the Circulatory System
ICD-9-CM equivalent
Converter →- 425.18Other hypertrophic cardiomyopathyexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about I42.2
Is I42.2 billable?
- Yes. I42.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I42.2 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I42.2 as a principal diagnosis.
Is I42.2 a CC or MCC?
- I42.2 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does I42.2 group to?
- I42.2 is used in the MS-DRG v44.0 logic for MS-DRG 314 (Other Circulatory System Diagnoses with MCC), MS-DRG 315 (Other Circulatory System Diagnoses with CC) and MS-DRG 316 (Other Circulatory System Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for I42.2?
- The CMS General Equivalence Mappings map I42.2 to ICD-9-CM 425.18.