Chapter 1: Certain Infectious and Parasitic Diseases
ICD-10-CM codes A00-B99
Covers infections caused by bacteria, viruses, fungi, and parasites, including tuberculosis, HIV, sepsis, pneumonia, urinary tract infections, and sexually transmitted diseases. These are among the most commonly coded conditions in emergency departments and inpatient settings.
A00-A09
Intestinal Infectious Diseases
A00Cholera
A01Typhoid and paratyphoid fevers
A02Other salmonella infections
A03Shigellosis
A04Other bacterial intestinal infections
A05Oth bacterial foodborne intoxications, NEC
A06Amebiasis
A07Other protozoal intestinal diseases
A08Viral and other specified intestinal infections
A09Infectious gastroenteritis and colitis, unspecified
A15-A19
Tuberculosis
A20-A28
Certain Zoonotic Bacterial Diseases
A30-A49
Other Bacterial Diseases
A30Leprosy [Hansen's disease]
A31Infection due to other mycobacteria
A32Listeriosis
A33Tetanus neonatorum
A34Obstetrical tetanus
A35Other tetanus
A36Diphtheria
A37Whooping cough
A38Scarlet fever
A39Meningococcal infection
A40Streptococcal sepsis
A41Other sepsis
A42Actinomycosis
A43Nocardiosis
A44Bartonellosis
A46Erysipelas
A48Other bacterial diseases, not elsewhere classified
A49Bacterial infection of unspecified site
A50-A64
Infections with a Predominantly Sexual Mode of Transmission
A50Congenital syphilis
A51Early syphilis
A52Late syphilis
A53Other and unspecified syphilis
A54Gonococcal infection
A55Chlamydial lymphogranuloma (venereum)
A56Other sexually transmitted chlamydial diseases
A57Chancroid
A58Granuloma inguinale
A59Trichomoniasis
A60Anogenital herpesviral [herpes simplex] infections
A63Oth predominantly sexually transmitted diseases, NEC
A64Unspecified sexually transmitted disease
A65-A69
Other Spirochetal Diseases
A70-A74
Other Diseases Caused by Chlamydiae
A75-A79
Rickettsioses
A80-A89
Viral Infections of the Central Nervous System
A80Acute poliomyelitis
A81Atypical virus infections of central nervous system
A82Rabies
A83Mosquito-borne viral encephalitis
A84Tick-borne viral encephalitis
A85Other viral encephalitis, not elsewhere classified
A86Unspecified viral encephalitis
A87Viral meningitis
A88Oth viral infections of central nervous system, NEC
A89Unspecified viral infection of central nervous system
A90-A99
Arthropod-Borne Viral Fevers and Viral Hemorrhagic Fevers
A90Dengue fever [classical dengue]
A91Dengue hemorrhagic fever
A92Other mosquito-borne viral fevers
A93Other arthropod-borne viral fevers, not elsewhere classified
A94Unspecified arthropod-borne viral fever
A95Yellow fever
A96Arenaviral hemorrhagic fever
A98Other viral hemorrhagic fevers, not elsewhere classified
A99Unspecified viral hemorrhagic fever
B00-B09
Viral Infections Characterized by Skin and Mucous Membrane Lesions
B00Herpesviral [herpes simplex] infections
B01Varicella [chickenpox]
B02Zoster [herpes zoster]
B03Smallpox
B04Monkeypox
B05Measles
B06Rubella [German measles]
B07Viral warts
B08Oth viral infect with skin and mucous membrane lesions, NEC
B09Unsp viral infection with skin and mucous membrane lesions
B10-B10
Other Human Herpesviruses
B15-B19
Viral Hepatitis
B20-B20
Human Immunodeficiency Virus [HIV] Disease
B25-B34
Other Viral Diseases
B35-B49
Mycoses
B35Dermatophytosis
B36Other superficial mycoses
B37Candidiasis
B38Coccidioidomycosis
B39Histoplasmosis
B40Blastomycosis
B41Paracoccidioidomycosis
B42Sporotrichosis
B43Chromomycosis and pheomycotic abscess
B44Aspergillosis
B45Cryptococcosis
B46Zygomycosis
B47Mycetoma
B48Other mycoses, not elsewhere classified
B49Unspecified mycosis
B50-B64
Protozoal Diseases
B50Plasmodium falciparum malaria
B51Plasmodium vivax malaria
B52Plasmodium malariae malaria
B53Other specified malaria
B54Unspecified malaria
B55Leishmaniasis
B56African trypanosomiasis
B57Chagas' disease
B58Toxoplasmosis
B59Pneumocystosis
B60Other protozoal diseases, not elsewhere classified
B64Unspecified protozoal disease
B65-B83
Helminthiases
B65Schistosomiasis [bilharziasis]
B66Other fluke infections
B67Echinococcosis
B68Taeniasis
B69Cysticercosis
B70Diphyllobothriasis and sparganosis
B71Other cestode infections
B72Dracunculiasis
B73Onchocerciasis
B74Filariasis
B75Trichinellosis
B76Hookworm diseases
B77Ascariasis
B78Strongyloidiasis
B79Trichuriasis
B80Enterobiasis
B81Other intestinal helminthiases, not elsewhere classified
B82Unspecified intestinal parasitism
B83Other helminthiases
B85-B89
Pediculosis, Acariasis and Other Infestations
B90-B94
Sequelae of Infectious and Parasitic Diseases
B95-B97
Bacterial and Viral Infectious Agents
B99-B99
Other Infectious Diseases
Frequently Asked Questions
What ICD-10 codes are in Chapter 1?
Chapter 1: Certain Infectious and Parasitic Diseases covers ICD-10-CM codes A00-B99. It contains 22 code blocks with 167 top-level categories.
What conditions does ICD-10 Chapter 1 cover?
Covers infections caused by bacteria, viruses, fungi, and parasites, including tuberculosis, HIV, sepsis, pneumonia, urinary tract infections, and sexually transmitted diseases. These are among the most commonly coded conditions in emergency departments and inpatient settings. This chapter includes codes from A00-B99.
How many code blocks are in Chapter 1?
Chapter 1 has 22 code blocks: A00-A09 (Intestinal Infectious Diseases), A15-A19 (Tuberculosis), A20-A28 (Certain Zoonotic Bacterial Diseases), A30-A49 (Other Bacterial Diseases), and 18 more.
Is there an ICD-11 equivalent of ICD-10 Chapter 1?
ICD-11 reorganizes many chapters compared to ICD-10. Some conditions in Chapter 1 may appear in different ICD-11 chapters. Use the ICD-10 to ICD-11 converter to find specific code equivalents.
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