Chapter 1

A00–B99: Certain Infectious and Parasitic Diseases

Certain Infectious and Parasitic Diseases diagnostic classification updated for 2026.

Chapter Instructions

Includes
  • diseases generally recognized as communicable or transmissible
Excludes1(Not coded here. Use a different code.)
  • certain localized infections - see body system-related chapters
Excludes2(Not included here. Code separately if applicable.)
  • carrier or suspected carrier of infectious disease (Z22.-)
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)
Use Additional Code
  • code to identify resistance to antimicrobial drugs (Z16.-)
Internal Codes
  • B97.19|

    Other enterovirus as the cause of diseases classified elsewhere

  • B97.21|

    SARS-associated coronavirus as the cause of diseases classified elsewhere

  • B97.29|

    Other coronavirus as the cause of diseases classified elsewhere

  • B97.30|

    Unspecified retrovirus as the cause of diseases classified elsewhere

  • B97.31|

    Lentivirus as the cause of diseases classified elsewhere

  • B97.32|

    Oncovirus as the cause of diseases classified elsewhere

  • B97.33|

    Human T-cell lymphotrophic virus, type I [HTLV-I] as the cause of diseases classified elsewhere

  • B97.34|

    Human T-cell lymphotrophic virus, type II [HTLV-II] as the cause of diseases classified elsewhere

  • B97.35|

    Human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere

  • B97.39|

    Other retrovirus as the cause of diseases classified elsewhere

  • B97.4|

    Respiratory syncytial virus as the cause of diseases classified elsewhere

  • B97.5|

    Reovirus as the cause of diseases classified elsewhere

  • B97.6|

    Parvovirus as the cause of diseases classified elsewhere

  • B97.7|

    Papillomavirus as the cause of diseases classified elsewhere

  • B97.81|

    Human metapneumovirus as the cause of diseases classified elsewhere

  • B97.89|

    Other viral agents as the cause of diseases classified elsewhere

  • B99.8|

    Other infectious disease

  • B99.9|

    Unspecified infectious disease

PreviousPage 22 of 22