I39 Endocarditis and heart valve disorders in diseases classified elsewhere
Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.
Excludes1 (never code together)
endocardial involvement in:
candidiasis (B37.6)
gonococcal infection (A54.83)
Libman-Sacks disease (M32.11)
listerosis (A32.82)
meningococcal infection (A39.51)
rheumatoid arthritis (M05.31)
syphilis (A52.03)
tuberculosis (A18.84)
typhoid fever (A01.02)
Code first
underlying disease, such as:
Q fever (A78)
Applies from I39 Endocarditis and heart valve disorders in diseases classified elsewhere
Excludes1 (never code together)
endocardial involvement in:
candidiasis (B37.6)
gonococcal infection (A54.83)
Libman-Sacks disease (M32.11)
listerosis (A32.82)
meningococcal infection (A39.51)
rheumatoid arthritis (M05.31)
syphilis (A52.03)
tuberculosis (A18.84)
typhoid fever (A01.02)
Code first
underlying disease, such as:
Q fever (A78)
MS-DRG index
Defines the logic of DRG(s) 306-307 in MDC 05.
Approximate ICD-9-CM (GEMs)
421.1 Acute and subacute infective endocarditis in diseases classified elsewhere (approximate)
424.91 Endocarditis in diseases classified elsewhere (approximate)
Medicare Code Edits (MCE v43.1 (April 2026))
Manifestation codes as principal diagnosis: Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and are not allowed as principal diagnosis.
Code annotations containing back-references to I39
Back-references to I39
Use Additional: B39 Histoplasmosis ("endocarditis (I39)")
Back-references to I39
Use Additional: B39 Histoplasmosis ("endocarditis (I39)")