Alphabetic Index FY2027

I43

Cardiomyopathy in diseases classified elsewhere

FY2027Chapter 9: Diseases of the circulatory system/I30–I5A Other forms of heart disease

BillableComplete code, valid to report
Care settingsHospice: not accepted as primaryHospital CC

I43 is a billable ICD-10-CM diagnosis code for cardiomyopathy in diseases classified elsewhere. It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 45 entries. Its coding notes include a Code first instruction, 5 Excludes1 entries and 10 Excludes2 entries.

Code first

If the underlying condition listed here is present and known, sequence it first.

This code

Excludes1

Not coded here. The listed conditions generally should not be reported together.

This code

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (10 notes)
Inherited from Chapter 9 Diseases of the circulatory system
  • 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.

Hospice: not accepted as primary

Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).

Source: CMS Integrated Outpatient Code Editor (IOCE) v27.3, effective October 1, 2026, edit 86

Hospital 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 C

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 45 entries

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