A00-B99
Certain infectious and parasitic diseases
Chapter coding notes
diseases generally recognized as communicable or transmissible
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)
code to identify resistance to antimicrobial drugs (Z16.-)
Blocks in this chapter
A00-A09
Intestinal infectious diseases
A15-A19
Tuberculosis
A20-A28
Certain zoonotic bacterial diseases
A30-A49
Other bacterial diseases
A50-A64
Infections with a predominantly sexual mode of transmission
A65-A69
Other spirochetal diseases
A70-A74
Other diseases caused by chlamydiae
A75-A79
Rickettsioses
A80-A89
Viral and prion infections of the central nervous system
A90-A99
Arthropod-borne viral fevers and viral hemorrhagic fevers
B00-B09
Viral infections characterized by skin and mucous membrane lesions
B10
Other human herpesviruses
B15-B19
Viral hepatitis
B20
Human immunodeficiency virus [HIV] disease
B25-B34
Other viral diseases
B35-B49
Mycoses
B50-B64
Protozoal diseases
B65-B83
Helminthiases
B85-B89
Pediculosis, acariasis and other infestations
B90-B94
Sequelae of infectious and parasitic diseases
B95-B97
Bacterial and viral infectious agents
B99
Other infectious diseases
Official Guidelines for Chapter 1
FY 2026 ›Subsections
- I.C.1.aHuman Immunodeficiency Virus (HIV) Infections
- I.C.1.bInfectious agents as the cause of diseases classified to other chapters
- I.C.1.cInfections resistant to antibiotics
- I.C.1.dSepsis, Severe Sepsis, and Septic Shock Infections resistant to antibiotics
- I.C.1.eMethicillin Resistant Staphylococcus aureus (MRSA) Conditions
- I.C.1.fZika virus infections
- I.C.1.gCoronavirus infections
Sections that reference codes in Chapter 1
- I.A.13Etiology/manifestation convention (“code first”, “use additional code” and “in diseases classified elsewhere” notes)A18.0General rules
- I.B.7Multiple coding for a single conditionB95General rules
- I.C.1.a.2)(a)HIV diseaseB20
- I.C.1.a.2)(b)Patient admitted for HIV-related conditionB20
- I.C.1.a.2)(c)Patient with HIV disease admitted for unrelated conditionB20
- I.C.1.a.2)(g)Previously diagnosed HIV-related illnessB20
- I.C.1.a.2)(h)HIV Infection in Pregnancy, Childbirth and the PuerperiumB20
- I.C.1.a.2)(j)HIV disease or HIV positive status managed by antiretroviral medicationB20
Showing 8 of 17 sections that reference this range. Browse all FY 2026 guidelines.