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FY2027 ICD-10-CM reference

I42.2: Other hypertrophic cardiomyopathy

By the HCC Buddy Coding Team

The official ICD-10-CM descriptor is Other hypertrophic cardiomyopathy. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.

Billable code. Verified against the official FY2027 order file.

CMS-HCC V28

  • HCC 227: Cardiomyopathy/Myocarditis · RAF 0.189, Community Non-Dual Aged (CNA)

Payment year 2027, 2026 dates of service. HCC from the CMS 2027 Initial ICD-10-CM Mappings; RAF from the CMS-HCC V28 relative factors. For 2027 dates of service, CMS has not yet published the payment year 2028 mappings.

CMS-HCC V24

Not used for payment year 2027 Medicare Advantage payment

ESRD

  • HCC 85: Congestive Heart Failure

Coefficient pending: payment year 2027 coefficients for this model are not yet verified, so no RAF is shown. Mapping: PY2026 CMS mapping; CMS 2027 initial file unchanged.

PACE

Source verification pending

RxHCC

  • HCC 186: Heart Failure

Coefficient pending: payment year 2027 coefficients for this model are not yet verified, so no RAF is shown. Mapping: PY2026 CMS mapping; CMS 2027 initial file unchanged.

HHS-HCC

Source verification pending

FY2027 Tabular instructions

Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.

Excludes2

certain conditions originating in the perinatal period (P04-P96)

Source: I00-I99 (chapter, inherited).

Excludes2

certain infectious and parasitic diseases (A00-B99)

Source: I00-I99 (chapter, inherited).

Excludes2

complications of pregnancy, childbirth and the puerperium (O00-O9A)

Source: I00-I99 (chapter, inherited).

Excludes2

congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)

Source: I00-I99 (chapter, inherited).

Excludes2

endocrine, nutritional and metabolic diseases (E00-E88)

Source: I00-I99 (chapter, inherited).

Excludes2

injury, poisoning and certain other consequences of external causes (S00-T88)

Source: I00-I99 (chapter, inherited).

Excludes2

neoplasms (C00-D49)

Source: I00-I99 (chapter, inherited).

Excludes2

symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: I00-I99 (chapter, inherited).

Excludes2

systemic connective tissue disorders (M30-M36)

Source: I00-I99 (chapter, inherited).

Excludes2

transient cerebral ischemic attacks and related syndromes (G45.-)

Source: I00-I99 (chapter, inherited).

Includes

myocardiopathy

Source: I42 (category, inherited).

Code first

pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4)

Source: I42 (category, inherited).

Excludes2

ischemic cardiomyopathy (I25.5)

Source: I42 (category, inherited).

Excludes2

peripartum cardiomyopathy (O90.3)

Source: I42 (category, inherited).

Excludes2

ventricular hypertrophy (I51.7)

Source: I42 (category, inherited).

Instructional note

Nonobstructive hypertrophic cardiomyopathy

Source: I42.2 (self, direct).

Source: CMS FY2027 Tabular List and Alphabetic Index.

Open Tabular instructions and code details

Compare the FY2027 additions, removals and billable-status changes

What does I42.2 mean in FY2027?

The official ICD-10-CM descriptor is Other hypertrophic cardiomyopathy. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.

Is I42.2 billable in FY2027?

The FY2027 order file marks I42.2 as billable. Check the complete Tabular instructions and documentation before assigning it.

Does I42.2 map to an HCC?

In the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service), I42.2 maps to CMS-HCC V28 HCC 227 (Cardiomyopathy/Myocarditis). For 2027 dates of service, CMS has not yet published the payment year 2028 mappings. Under the PY2026 CMS mapping; CMS 2027 initial file unchanged: ESRD HCC 85; RxHCC HCC 186. Coefficients for these models are pending verification for payment year 2027. CMS-HCC V24, PACE and HHS-HCC mappings are still pending verification for FY2027.

Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.

Review the FY2026 April edition