Specific code 2014 ICD-9-CM Diagnosis Code 420.91
Acute idiopathic pericarditis
  • Billable Code
  • Short description: Ac idiopath pericarditis.
  • ICD-9-CM 420.91 will be replaced by an equivalent ICD-10-CM code (or codes) when the United States transitions from ICD-9-CM to ICD-10-CM on October 1, 2015.
  • ICD-9-CM 420.91 is a billable medical code that can be used to specify a diagnosis on a reimbursement claim.
Disease Synonyms
  • Acute idiopathic pericarditis (inflamed heart sac)
  • Pericarditis, acute, idiopathic
  • Viral pericarditis
Applies To
  • Pericarditis, acute:
    • benign
    • nonspecific
    • viral
Convert to ICD-10-CM: 420.91 converts directly to:
  • 2014 ICD-10-CM I30.0 Acute nonspecific idiopathic pericarditis
ICD-9-CM Volume 2 Index entries containing back-references to 420.91:
  • Pericarditis (granular) (with decompensation) (with effusion) 423.9
    • acute (nonrheumatic) 420.90
      • with chorea (acute) (rheumatic) (Sydenham's) 392.0
      • bacterial 420.99
      • benign 420.91
      • hemorrhagic 420.90
      • idiopathic 420.91
      • infective 420.90
      • nonspecific 420.91
      • rheumatic 391.0
        • with chorea (acute) (rheumatic) (Sydenham's) 392.0
      • sicca 420.90
      • viral 420.91
    • idiopathic (acute) 420.91
    • nonspecific 420.91
    • viral (acute) 420.91
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 420.91 is one of thousands of ICD-9-CM codes used in healthcare. Although ICD-9-CM and CPT codes are largely numeric, they differ in that CPT codes describe medical procedures and services. Can't find a code? Start at the root of ICD-9-CM, check the 2014 ICD-9-CM Index or use the search engine at the top of this page to lookup any code.