| Z20 | Contact with and (suspected) exposure to communicable diseases |
| Z20.0 | Contact with and (suspected) exposure to intestinal infectious diseases |
| Z20.01 | Contact with and (suspected) exposure to intestinal infectious diseases due to Escherichia coli (E. coli) |
| Z20.09 | Contact with and (suspected) exposure to other intestinal infectious diseases |
| Z20.1 | Contact with and (suspected) exposure to tuberculosis |
| Z20.2 | Contact with and (suspected) exposure to infections with a predominantly sexual mode of transmission |
| Z20.3 | Contact with and (suspected) exposure to rabies |
| Z20.4 | Contact with and (suspected) exposure to rubella |
| Z20.5 | Contact with and (suspected) exposure to viral hepatitis |
| Z20.6 | Contact with and (suspected) exposure to human immunodeficiency virus [HIV] |
| Z20.7 | Contact with and (suspected) exposure to pediculosis, acariasis and other infestations |
| Z20.8 | Contact with and (suspected) exposure to other communicable diseases |
| Z20.81 | Contact with and (suspected) exposure to other bacterial communicable diseases |
| Z20.810 | Contact with and (suspected) exposure to anthrax |
| Z20.811 | Contact with and (suspected) exposure to meningococcus |
| Z20.818 | Contact with and (suspected) exposure to other bacterial communicable diseases |
| Z20.82 | Contact with and (suspected) exposure to other viral communicable diseases |
| Z20.820 | Contact with and (suspected) exposure to varicella |
| Z20.828 | Contact with and (suspected) exposure to other viral communicable diseases |
| Z20.89 | Contact with and (suspected) exposure to other communicable diseases |
| Z20.9 | Contact with and (suspected) exposure to unspecified communicable disease |
| Z21 | Asymptomatic human immunodeficiency virus [HIV] infection status |
| Z22 | Carrier of infectious disease |
| Z22.0 | Carrier of typhoid |
| Z22.1 | Carrier of other intestinal infectious diseases |
| Z22.2 | Carrier of diphtheria |
| Z22.3 | Carrier of other specified bacterial diseases |
| Z22.31 | Carrier of bacterial disease due to meningococci |
| Z22.32 | Carrier of bacterial disease due to staphylococci |
| Z22.321 | Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus |
| Z22.322 | Carrier or suspected carrier of Methicillin resistant Staphylococcus aureus |
| Z22.33 | Carrier of bacterial disease due to streptococci |
| Z22.330 | Carrier of Group B streptococcus |
| Z22.338 | Carrier of other streptococcus |
| Z22.39 | Carrier of other specified bacterial diseases |
| Z22.4 | Carrier of infections with a predominantly sexual mode of transmission |
| Z22.5 | Carrier of viral hepatitis |
| Z22.50 | Carrier of unspecified viral hepatitis |
| Z22.51 | Carrier of viral hepatitis B |
| Z22.52 | Carrier of viral hepatitis C |
| Z22.59 | Carrier of other viral hepatitis |
| Z22.6 | Carrier of human T-lymphotropic virus type-1 [HTLV-1] infection |
| Z22.8 | Carrier of other infectious diseases |
| Z22.9 | Carrier of infectious disease, unspecified |
| Z23 | Encounter for immunization |
| Z28 | Immunization not carried out and underimmunization status |
| Z28.0 | Immunization not carried out because of contraindication |
| Z28.01 | Immunization not carried out because of acute illness of patient |
| Z28.02 | Immunization not carried out because of chronic illness or condition of patient |
| Z28.03 | Immunization not carried out because of immune compromised state of patient |
| Z28.04 | Immunization not carried out because of patient allergy to vaccine or component |
| Z28.09 | Immunization not carried out because of other contraindication |
| Z28.1 | Immunization not carried out because of patient decision for reasons of belief or group pressure |
| Z28.2 | Immunization not carried out because of patient decision for other and unspecified reason |
| Z28.20 | Immunization not carried out because of patient decision for unspecified reason |
| Z28.21 | Immunization not carried out because of patient refusal |
| Z28.29 | Immunization not carried out because of patient decision for other reason |
| Z28.3 | Underimmunization status |
| Z28.8 | Immunization not carried out for other reason |
| Z28.81 | Immunization not carried out due to patient having had the disease |
| Z28.82 | Immunization not carried out because of caregiver refusal |
| Z28.89 | Immunization not carried out for other reason |
| Z28.9 | Immunization not carried out for unspecified reason |