 This study examines and describes the methods used to determine immunization coverage in Canada, and compares routine infant and childhood coverage estimates derived from the Canadian 2013 Childhood National Immunization Coverage Survey, CNICS, with estimates collected from provinces and territories, PETS. The study found that different methodologies for measuring coverage are used across PETS, including valid doses, and grace periods. Most PETS measure up to date, united, coverage, and for also assess on-time coverage. The degree of concordance between PET, T, and CNICS coverage estimates varied by jurisdiction, antigen, and age group. Comparisons between PET, T, and CNICS estimates leave remaining questions about the proportion of children fully vaccinated in Canada. This article was authored by Sarah E. Wilson, Susan Quach, Shannon E. MacDonald, and others. We are article.tv, links in the description below.