ICD-10-CM — Chapter 1

Certain infectious and parasitic diseases - Chapter 1 includes Human Immunodeficiency Virus (HIV) infections, infectious agents, infections resistant to antibiotics, Sepsis, Severe Sepsis, and Septic Shock, MRSA, and other infectious diseases and conditions.

Tabular List

Find your ICD-10-CM code by first selecting the most applicable chapter

Certain infectious and parasitic diseases

- Chapter 1 includes Human Immunodeficiency Virus (HIV) infections, infectious agents, infections resistant to antibiotics, Sepsis, Severe Sepsis, and Septic Shock, MRSA, and other infectious diseases and conditions.


  • diseases generally recognized as communicable or transmissible

Use additional code to identify resistance to antimicrobial drugs (Z16.-)


  • certain localized infections - see body system-related chapters


  • 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)
Expand All Chapter #1 contains the following ICD-10-CM sections:
  • A00 Cholera

  • A01 Typhoid and paratyphoid fevers

  • A02 Other salmonella infections

  • A03 Shigellosis

  • A04 Other bacterial intestinal infections

  • A05 Other bacterial foodborne intoxications, not elsewhere classified

  • A06 Amebiasis

  • A07 Other protozoal intestinal diseases

  • A08 Viral and other specified intestinal infections

  • A09 Infectious gastroenteritis and colitis, unspecified

    Inclusion term(s):

    • Infectious colitis NOS
    • Infectious enteritis NOS
    • Infectious gastroenteritis NOS


  • infections due to Mycobacterium tuberculosis and Mycobacterium bovis


  • congenital tuberculosis (P37.0)
  • nonspecific reaction to test for tuberculosis without active tuberculosis (R76.1-)
  • pneumoconiosis associated with tuberculosis, any type in A15 (J65)
  • positive PPD (R76.11)
  • positive tuberculin skin test without active tuberculosis (R76.11)
  • sequelae of tuberculosis (B90.-)
  • silicotuberculosis (J65)
  • A15 Respiratory tuberculosis

  • A17 Tuberculosis of nervous system

  • A18 Tuberculosis of other organs

  • A19 Miliary tuberculosis

  • A20 Plague

  • A21 Tularemia

  • A22 Anthrax

  • A23 Brucellosis

  • A24 Glanders and melioidosis

  • A25 Rat-bite fevers

  • A26 Erysipeloid

  • A27 Leptospirosis

  • A28 Other zoonotic bacterial diseases, not elsewhere classified

  • A30 Leprosy [Hansen's disease]

  • A31 Infection due to other mycobacteria

  • A32 Listeriosis

  • A33 Tetanus neonatorum

  • A34 Obstetrical tetanus

  • A35 Other tetanus

    Inclusion term(s):

    • Tetanus NOS
  • A36 Diphtheria

  • A37 Whooping cough

  • A38 Scarlet fever

  • A39 Meningococcal infection

  • A40 Streptococcal sepsis

  • A41 Other sepsis

  • A42 Actinomycosis

  • A43 Nocardiosis

  • A44 Bartonellosis

  • A46 Erysipelas

  • A48 Other bacterial diseases, not elsewhere classified

  • A49 Bacterial infection of unspecified site


  • nonspecific and nongonococcal urethritis (N34.1)
  • Reiter's disease (M02.3-)


  • human immunodeficiency virus [HIV] disease (B20)
  • A50 Congenital syphilis

  • A51 Early syphilis

  • A52 Late syphilis

  • A53 Other and unspecified syphilis

  • A54 Gonococcal infection

  • A55 Chlamydial lymphogranuloma (venereum)

    Inclusion term(s):

    • Climatic or tropical bubo
    • Durand-Nicolas-Favre disease
    • Esthiomene
    • Lymphogranuloma inguinale
  • A56 Other sexually transmitted chlamydial diseases

  • A57 Chancroid

    Inclusion term(s):

    • Ulcus molle
  • A58 Granuloma inguinale

    Inclusion term(s):

    • Donovanosis
  • A59 Trichomoniasis

  • A60 Anogenital herpesviral [herpes simplex] infections

  • A63 Other predominantly sexually transmitted diseases, not elsewhere classified

  • A64 Unspecified sexually transmitted disease



  • sexually transmitted chlamydial diseases (A55-A56)
  • A70 Chlamydia psittaci infections

    Inclusion term(s):

    • Ornithosis
    • Parrot fever
    • Psittacosis
  • A71 Trachoma

  • A74 Other diseases caused by chlamydiae

  • A75 Typhus fever

  • A77 Spotted fever [tick-borne rickettsioses]

  • A78 Q fever

    Inclusion term(s):

    • Infection due to Coxiella burnetii
    • Nine Mile fever
    • Quadrilateral fever
  • A79 Other rickettsioses


  • postpolio syndrome (G14)
  • sequelae of poliomyelitis (B91)
  • sequelae of viral encephalitis (B94.1)
  • A80 Acute poliomyelitis

  • A81 Atypical virus infections of central nervous system

  • A82 Rabies

  • A83 Mosquito-borne viral encephalitis

  • A84 Tick-borne viral encephalitis

  • A85 Other viral encephalitis, not elsewhere classified

  • A86 Unspecified viral encephalitis

    Inclusion term(s):

    • Viral encephalomyelitis NOS
    • Viral meningoencephalitis NOS
  • A87 Viral meningitis

  • A88 Other viral infections of central nervous system, not elsewhere classified

  • A89 Unspecified viral infection of central nervous system

  • A90 Dengue fever [classical dengue]

  • A91 Dengue hemorrhagic fever

  • A92 Other mosquito-borne viral fevers

  • A93 Other arthropod-borne viral fevers, not elsewhere classified

  • A94 Unspecified arthropod-borne viral fever

    Inclusion term(s):

    • Arboviral fever NOS
    • Arbovirus infection NOS
  • A95 Yellow fever

  • A96 Arenaviral hemorrhagic fever

  • A98 Other viral hemorrhagic fevers, not elsewhere classified

  • A99 Unspecified viral hemorrhagic fever

  • B00 Herpesviral [herpes simplex] infections

  • B01 Varicella [chickenpox]

  • B02 Zoster [herpes zoster]

  • B03 Smallpox

    Note: In 1980 the 33rd World Health Assembly declared that smallpox had been eradicated.
    The classification is maintained for surveillance purposes.

  • B04 Monkeypox

  • B05 Measles

  • B06 Rubella [German measles]

  • B07 Viral warts

  • B08 Other viral infections characterized by skin and mucous membrane lesions, not elsewhere classified

  • B09 Unspecified viral infection characterized by skin and mucous membrane lesions

    Inclusion term(s):

    • Viral enanthema NOS
    • Viral exanthema NOS
  • B10 Other human herpesviruses


  • sequelae of viral hepatitis (B94.2)


  • cytomegaloviral hepatitis (B25.1)
  • herpesviral [herpes simplex] hepatitis (B00.81)
  • B15 Acute hepatitis A

  • B16 Acute hepatitis B

  • B17 Other acute viral hepatitis

  • B18 Chronic viral hepatitis

  • B19 Unspecified viral hepatitis

  • B20 Human immunodeficiency virus [HIV] disease

  • B25 Cytomegaloviral disease

  • B26 Mumps

  • B27 Infectious mononucleosis

  • B30 Viral conjunctivitis

  • B33 Other viral diseases, not elsewhere classified

  • B34 Viral infection of unspecified site


  • hypersensitivity pneumonitis due to organic dust (J67.-)
  • mycosis fungoides (C84.0-)
  • B35 Dermatophytosis

  • B36 Other superficial mycoses

  • B37 Candidiasis

  • B38 Coccidioidomycosis

  • B39 Histoplasmosis

  • B40 Blastomycosis

  • B41 Paracoccidioidomycosis

  • B42 Sporotrichosis

  • B43 Chromomycosis and pheomycotic abscess

  • B44 Aspergillosis

  • B45 Cryptococcosis

  • B46 Zygomycosis

  • B47 Mycetoma

  • B48 Other mycoses, not elsewhere classified

  • B49 Unspecified mycosis

    Inclusion term(s):

    • Fungemia NOS


  • amebiasis (A06.-)
  • other protozoal intestinal diseases (A07.-)
  • B50 Plasmodium falciparum malaria

  • B51 Plasmodium vivax malaria

  • B52 Plasmodium malariae malaria

  • B53 Other specified malaria

  • B54 Unspecified malaria

  • B55 Leishmaniasis

  • B56 African trypanosomiasis

  • B57 Chagas' disease

  • B58 Toxoplasmosis

  • B59 Pneumocystosis

    Inclusion term(s):

    • Pneumonia due to Pneumocystis carinii
    • Pneumonia due to Pneumocystis jiroveci
  • B60 Other protozoal diseases, not elsewhere classified

  • B64 Unspecified protozoal disease

  • B65 Schistosomiasis [bilharziasis]

  • B66 Other fluke infections

  • B67 Echinococcosis

  • B68 Taeniasis

  • B69 Cysticercosis

  • B70 Diphyllobothriasis and sparganosis

  • B71 Other cestode infections

  • B72 Dracunculiasis

  • B73 Onchocerciasis

  • B74 Filariasis

  • B75 Trichinellosis

  • B76 Hookworm diseases

  • B77 Ascariasis

  • B78 Strongyloidiasis

  • B79 Trichuriasis

  • B80 Enterobiasis

  • B81 Other intestinal helminthiases, not elsewhere classified

  • B82 Unspecified intestinal parasitism

  • B83 Other helminthiases

Categories B90-B94 are to be used to indicate conditions in categories A00-B89 as the cause of sequelae, which are themselves classified elsewhere. The 'sequelae' include conditions specified as such; they also include residuals of diseases classifiable to the above categories if there is evidence that the disease itself is no longer present. Codes from these categories are not to be used for chronic infections. Code chronic current infections to active infectious disease as appropriate.

  • B90 Sequelae of tuberculosis

  • B91 Sequelae of poliomyelitis

  • B92 Sequelae of leprosy

  • B94 Sequelae of other and unspecified infectious and parasitic diseases

These categories are provided for use as supplementary or additional codes to identify the infectious agent(s) in diseases classified elsewhere.

  • B95 Streptococcus, Staphylococcus, and Enterococcus as the cause of diseases classified elsewhere

  • B96 Other bacterial agents as the cause of diseases classified elsewhere

  • B97 Viral agents as the cause of diseases classified elsewhere

  • B99 Other and unspecified infectious diseases