- ICD-10-CM International Classification of Disease, Tenth Revision, (ICD-10-CM)
- ICF – (International Classification of Functioning, Disability and Health) (ICF)
- Illicit Drug Use — see Persons Who Use Drugs
- Image Library, Public Health — see Public Health Image Library
- Immigrant and Refugee Health
- IMMPaCt (International Micronutrient Malnutrition Prevention and Control Program) — see Micronutrients
- Immunization
- Vaccine Information Statements (VIS)
- Vaccine-Preventable Diseases and Specific Vaccines
- Immunization and Pregnancy — see Pregnancy and Vaccination
- Immunization and Respiratory Diseases, CDC National Center for
- Immunization Information Systems (IIS) — see Immunization Registries
- Immunization Practices, Advisory Committee on — see Advisory Committee on Immunization Practices (ACIP)
- Immunization Quality Improvement Strategy — see AFIX Immunization Strategy
- Immunization Registries
- Immunization Schedules
- Immunization Works!
- Impaired Driving
- Import Permit Program (IPP)
- Importation of Animals, Animal Products
- Improving Antimicrobial Use/Prescribing in Hospitals — see Antibiotic Stewardship
- In Vitro Fertilization — see Assisted Reproductive Technology (ART)
- Indoor Environmental Quality
- Industry and Occupation Coding
- Infant and Toddler Nutrition
- Infant Death — see Infant Mortality
- Infant Mortality
- Infants
- Infection Control
- Infection Control, International — see International Infection Control
- Infectious Mononucleosis — see Epstein-Barr Virus Infection (EBV Infection)
- Infertility
- Inflammatory Bowel Disease (IBD)
- Influenza
- Influenza and Cancer — see Cancer and Flu
- Influenza in Pigs — see Swine Influenza
- Influenza Surveillance Data
- Influenza Vaccination
- Influenza Vaccination Coverage
- FluVaxView
- Influenza Versus Cold — see Cold Versus Flu
- Influenza, Avian — see Avian Influenza
- Influenza, International — see International Flu
- Influenza, Pandemic — see Pandemic Flu
- Informatics and Data Science Workforce Programs (IDSWD)
- Informatics Fellowship Program, Public Health — see Public Health Informatics Fellowship Program (PHIFP)
- Information Quality
- Information Technology (IT)
- Injection Safety
- Injury and Violence Prevention
- Injury Center
- Injury Prevention in American Indian and Alaska Native Communities
- Injury Statistics
- Insect Repellent Use and Safety
- Insects and Scorpions
- Institutional Animal Care and Use Committee (IACUC)
- Institutional Review Boards
- Insulin
- Interagency Food Safety Analytics Collaboration (IFSAC)
- International Flu
- International Health — see Global Health
- International Infection Control
- International Micronutrient Malnutrition Prevention & Control Program (IMMPaCt) — see Micronutrients
- International Travel with Pets, for Healthcare Providers — see Pets and International Travel, for Healthcare Providers
- Interstitial Cystitis (IC)
- Intimate Partner Violence
- Invasive Candidiasis — see Candidiasis
- IPV — see Intimate Partner Violence
- IRB — see Institutional Review Boards
- Irradiation — see Food Irradiation
- Island Affairs
- Isolation and Quarantine — see Port Health
It's never too early or too late to work towards being the healthiest you.