- Mad Cow Disease — Bovine Spongiform Encephalopathy (BSE)
- Malaria
- Mammograms
- Breast Cancer
- Mansonellosis — see Filarial Worms
- Manual for the Surveillance of Vaccine-Preventable Diseases
- Manufacturing
- Marburg Virus Disease
- Marine Toxins
- Maritime Safety and Health Program
- Marriage Certificates — see Vital Records
- Marriage Data
- Maternal Mortality
- Mayaro Virus Infection
- Meaningful Use
- Measles
- Measles Vaccination
- Measles, Mumps, Rubella, Varicella (MMRV) Vaccine Safety
- Medical Students, Epidemiology Elective Program for — see Epidemiology Elective Program for Senior Medical and Veterinary Students
- Medication and Pregnancy — see Treating for Two
- Medication Safety
- Melioidosis
- Meningitis
- Meningococcal Disease
- Meningococcal Vaccination
- Mental Health
- Mental Health and Disasters
- Mercury
- Mercury and Vaccines — see Thimerosal (Mercury) and Vaccines
- Mesothelioma
- Methicillin-Resistant Staphylococcus aureus Infection (MRSA)
- Mexico—United States Public Health — see Border Health and Migration
- Microalgal Bloom-Associated Illness (HAB) — see Harmful Algal Bloom (HAB)-Associated Illness (HAB)
- MicrobeNet
- Microcephaly
- Micronutrients
- Microsporidia Infection
- Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
- Coronavirus
- Migrant, Refugee, and Immigrant Health — see Immigrant and Refugee Health
- Migration and Border Health — see Border Health and Migration
- Milk, Raw — see Raw Milk
- Million Hearts®
- Mining
- Minority Health
- Mission and Vision, CDC — see CDC Mission and Vision
- MMR Vaccination
- MMRV Vaccine and Febrile Seizures — see Febrile Seizures and MMRV Vaccine
- Mobile
- Model Aquatic Health Code (MAHC)
- Modern Initiative
- Mold
- Molluscum Contagiosum
- Monkey B virus — see B virus Infection
- Mononucleosis, Infectious — see Epstein-Barr Virus Infection (EBV Infection)
- Monosodium Glutamate — see Vaccine Ingredients
- Morbidity & Mortality Weekly Report (MMWR)
- Mortality Data
- Life Expectancy
- Mosquitoes
- Mother to Child HIV Transmission, Global Prevention — see Prevention of Mother to Child HIV Transmission Globally
- Motor Vehicle Injuries
- Mpox (formerly known as Monkeypox)
- MRSA — see Methicillin-Resistant Staphylococcus aureus Infection (MRSA)
- Mucormycete Infection
- Mucormycosis — see Mucormycete Infection
- Mucus — see Cold, Common
- Multiple organ dysfunction syndrome — see Sepsis
- Multistate Foodborne Outbreaks — see Foodborne Outbreaks
- Mumps
- Mumps Vaccination
- Murine (Flea-borne) Typhus — see Typhus Fevers
- Muscular Dystrophy (MD)
- Musculoskeletal Disorders — see Ergonomic and Musculoskeletal Disorders
- Museum, CDC
- Mustard Gas (H, HD, and HT)
- Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS)
- Mycetoma
- Mycobacterium tuberculosis Infection — see Tuberculosis (TB)
- Mycoplasma pneumoniae Infection
- Myelomeningocele — see Spina Bifida
- Myiasis
It's never too early or too late to work towards being the healthiest you.