Alphabetic Index FY2027

I09.1

Rheumatic diseases of endocardium, valve unspecified

FY2027Chapter 9: Diseases of the circulatory system/I05–I09 Chronic rheumatic heart diseases

BillableComplete code, valid to report
Care settingsHome Health Primary · MMTA - Cardiac and Circulatory

I09.1 (also written I091) is a billable ICD-10-CM diagnosis code for rheumatic diseases of endocardium, valve unspecified. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 6 codes in category I09 (Other rheumatic heart diseases). The Alphabetic Index lists it under 3 entries. Its coding notes include 1 Excludes1 entry and 10 Excludes2 entries.

Excludes1

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

This code
  • endocarditis, valve unspecified (I38)

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.

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, 2026

Inclusion terms

Conditions classified to this code.

This code
  • Rheumatic endocarditis (chronic)
  • Rheumatic valvulitis (chronic)

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 3 entries