ICD-10-CM Section · Z20-Z29
Persons with potential health hazards related to communicable diseases
85 codes in this section
85
Total Codes
65
Billable
20
Header (Non-Billable)
6
Top-Level Codes
About Section Z20-Z29
Section Z20-Z29 (Z20-Z29) covers persons with potential health hazards related to communicable diseases. It sits within the Factors influencing health status and contact with health services chapter (Z00-Z99). This section contains 85 ICD-10-CM codes, 65 billable diagnoses you can submit on a claim, and 20 non-billable header codes used to organize the hierarchy.
Codes are organized below by 3-character root. Click the root to see all subcodes underneath it, or click any individual code for full coverage data, payer policies, and linked CPT procedures.
Codes in Z20-Z29
Grouped by 3-character root code. Click any code for full detail.
Z20
Contact with and (suspected) exposure to communicable diseases
22 subcodes
| Z20.0 | Contact with and (suspected) exposure to intestinal infectious diseases | Header |
| Z20.01 | Contact with and (suspected) exposure to intestinal infectious diseases due to Escherichia coli (E. coli) | Billable |
| Z20.09 | Contact with and (suspected) exposure to other intestinal infectious diseases | Billable |
| Z20.1 | Contact with and (suspected) exposure to tuberculosis | Billable |
| Z20.2 | Contact with and (suspected) exposure to infections with a predominantly sexual mode of transmission | Billable |
| Z20.3 | Contact with and (suspected) exposure to rabies | Billable |
| Z20.4 | Contact with and (suspected) exposure to rubella | Billable |
| Z20.5 | Contact with and (suspected) exposure to viral hepatitis | Billable |
| Z20.6 | Contact with and (suspected) exposure to human immunodeficiency virus [HIV] | Billable |
| Z20.7 | Contact with and (suspected) exposure to pediculosis, acariasis and other infestations | Billable |
| Z20.8 | Contact with and (suspected) exposure to other communicable diseases | Header |
| Z20.81 | Contact with and (suspected) exposure to other bacterial communicable diseases | Header |
| Z20.810 | Contact with and (suspected) exposure to anthrax | Billable |
| Z20.811 | Contact with and (suspected) exposure to meningococcus | Billable |
| Z20.818 | Contact with and (suspected) exposure to other bacterial communicable diseases | Billable |
| Z20.82 | Contact with and (suspected) exposure to other viral communicable diseases | Header |
| Z20.820 | Contact with and (suspected) exposure to varicella | Billable |
| Z20.821 | Contact with and (suspected) exposure to Zika virus | Billable |
| Z20.822 | Contact with and (suspected) exposure to COVID-19 | Billable |
| Z20.828 | Contact with and (suspected) exposure to other viral communicable diseases | Billable |
| Z20.89 | Contact with and (suspected) exposure to other communicable diseases | Billable |
| Z20.9 | Contact with and (suspected) exposure to unspecified communicable disease | Billable |
Z21
Asymptomatic human immunodeficiency virus [HIV] infection status
0 subcodes
Z22
Carrier of infectious disease
25 subcodes
| Z22.0 | Carrier of typhoid | Billable |
| Z22.1 | Carrier of other intestinal infectious diseases | Billable |
| Z22.2 | Carrier of diphtheria | Billable |
| Z22.3 | Carrier of other specified bacterial diseases | Header |
| Z22.31 | Carrier of bacterial disease due to meningococci | Billable |
| Z22.32 | Carrier of bacterial disease due to staphylococci | Header |
| Z22.321 | Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus | Billable |
| Z22.322 | Carrier or suspected carrier of Methicillin resistant Staphylococcus aureus | Billable |
| Z22.33 | Carrier of bacterial disease due to streptococci | Header |
| Z22.330 | Carrier of Group B streptococcus | Billable |
| Z22.338 | Carrier of other streptococcus | Billable |
| Z22.34 | Carrier of Acinetobacter baumannii | Header |
| Z22.340 | Carrier of carbapenem-resistant Acinetobacter baumannii | Billable |
| Z22.341 | Carrier of carbapenem-sensitive Acinetobacter baumannii | Billable |
| Z22.349 | Carrier of Acinetobacter baumannii, unspecified | Billable |
| Z22.35 | Carrier of Enterobacterales | Header |
| Z22.350 | Carrier of carbapenem-resistant Enterobacterales | Billable |
| Z22.358 | Carrier of other Enterobacterales | Billable |
| Z22.359 | Carrier of Enterobacterales, unspecified | Billable |
| Z22.39 | Carrier of other specified bacterial diseases | Billable |
| Z22.4 | Carrier of infections with a predominantly sexual mode of transmission | Billable |
| Z22.6 | Carrier of human T-lymphotropic virus type-1 [HTLV-1] infection | Billable |
| Z22.7 | Latent tuberculosis | Billable |
| Z22.8 | Carrier of other infectious diseases | Billable |
| Z22.9 | Carrier of infectious disease, unspecified | Billable |
Z23
Encounter for immunization
0 subcodes
Z28
Immunization not carried out and underimmunization status
22 subcodes
| Z28.0 | Immunization not carried out because of contraindication | Header |
| Z28.01 | Immunization not carried out because of acute illness of patient | Billable |
| Z28.02 | Immunization not carried out because of chronic illness or condition of patient | Billable |
| Z28.03 | Immunization not carried out because of immune compromised state of patient | Billable |
| Z28.04 | Immunization not carried out because of patient allergy to vaccine or component | Billable |
| Z28.09 | Immunization not carried out because of other contraindication | Billable |
| Z28.1 | Immunization not carried out because of patient decision for reasons of belief or group pressure | Billable |
| Z28.2 | Immunization not carried out because of patient decision for other and unspecified reason | Header |
| Z28.20 | Immunization not carried out because of patient decision for unspecified reason | Billable |
| Z28.21 | Immunization not carried out because of patient refusal | Billable |
| Z28.29 | Immunization not carried out because of patient decision for other reason | Billable |
| Z28.3 | Underimmunization status | Header |
| Z28.31 | Underimmunization for COVID-19 status | Header |
| Z28.310 | Unvaccinated for COVID-19 | Billable |
| Z28.311 | Partially vaccinated for COVID-19 | Billable |
| Z28.39 | Other underimmunization status | Billable |
| Z28.8 | Immunization not carried out for other reason | Header |
| Z28.81 | Immunization not carried out due to patient having had the disease | Billable |
| Z28.82 | Immunization not carried out because of caregiver refusal | Billable |
| Z28.83 | Immunization not carried out due to unavailability of vaccine | Billable |
| Z28.89 | Immunization not carried out for other reason | Billable |
| Z28.9 | Immunization not carried out for unspecified reason | Billable |
Z29
Encounter for other prophylactic measures
10 subcodes
| Z29.1 | Encounter for prophylactic immunotherapy | Header |
| Z29.11 | Encounter for prophylactic immunotherapy for respiratory syncytial virus (RSV) | Billable |
| Z29.12 | Encounter for prophylactic antivenin | Billable |
| Z29.13 | Encounter for prophylactic Rho(D) immune globulin | Billable |
| Z29.14 | Encounter for prophylactic rabies immune globin | Billable |
| Z29.3 | Encounter for prophylactic fluoride administration | Billable |
| Z29.8 | Encounter for other specified prophylactic measures | Header |
| Z29.81 | Encounter for HIV pre-exposure prophylaxis | Billable |
| Z29.89 | Encounter for other specified prophylactic measures | Billable |
| Z29.9 | Encounter for prophylactic measures, unspecified | Billable |
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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