421.9 AC/SUBAC ENDOCARDIT NOS


Code Information

Diagnosis Code: 421.9

Short Description: Ac/subac endocardit NOS

Long Description: Acute endocarditis, unspecified

Code Classification:

  • Diseases of the circulatory system (390–459)
    • Other forms of heart disease (420-429)
      • 421 Acute and subacute endocarditis
        • 421.9 Ac/subac endocardit NOS

Code Version: 2015 ICD-9-CM


References to Index of Diseases and Injuries

The code 421.9 has the following ICD-9-CM references to the Index of Diseases and Injuries
  • Endocarditis (chronic) (indeterminate) (interstitial) (marantic) (nonbacterial thrombotic) (residual) (sclerotic) (sclerous) (senile) (valvular) 424.90
    • acute or subacute 421.9
      • rheumatic (aortic) (mitral) (pulmonary) (tricuspid) 391.1
        • with chorea (acute) (rheumatic) (Sydenham's) 392.0
    • aortic (heart) (nonrheumatic) (valve) 424.1
      • acute or subacute 421.9
    • mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea) 394.9
      • nonrheumatic 424.0
        • acute or subacute 421.9
    • pulmonary (chronic) (heart) (valve) 424.3
      • acute or subacute 421.9
        • rheumatic 391.1
          • with chorea (acute) (rheumatic) (Sydenham's) 392.0
    • toxic (see also Endocarditis, acute) 421.9
    • tricuspid (chronic) (heart) (inactive) (rheumatic) (valve) (with chorea) 397.0
      • nonrheumatic 424.2
        • acute or subacute 421.9
  • Myoendocarditis - see also Endocarditis
    • acute or subacute 421.9
  • Periendocarditis (see also Endocarditis) 424.90
    • acute or subacute 421.9

Crosswalk Information

The code 421.9 converts into the following ICD-10 code(s):
ICD-9 Code ICD-10 Code ICD-10 Description
421.9 Right Arrow I33.9 Acute and subacute endocarditis, unspecified
This ICD-9 to ICD-10 data is based on the 2018 General Equivalency Mapping (GEM) files published by the Centers for Medicare & Medicaid Services (CMS) for informational purposes only. The data is not an ICD-10 conversion tool and doesn’t guarantee clinical accuracy.

Similar Codes

ICD-9 Code ICD-9 Description
421.0 Acute and subacute bacterial endocarditis
421.1 Acute and subacute infective endocarditis in diseases classified elsewhere


This page was last updated on: 10/1/2014