The Immunization Delivery Cost Catalogue (IDCC) is the most comprehensive, current, and standardized global evidence on the cost of delivering vaccines. In January 2017 and again in April 2018 and December 2019, ThinkWell completed a systematic review of the current evidence base on immunization delivery costs (IDC)*. The IDCC was built to answer a question frequently asked by national and global immunization stakeholders: “What are the unit costs of vaccine delivery across different LMICs and through a variety of delivery strategies?” The IDCC is available as a web catalog and as a downloadable Excel document. This review, and subsequent updates, ensures that IDC evidence is globally accessible and easy to interpret. Over 17,000 resources from January 2005 to March 2019 were reviewing including published and grey literature. Data from 68 articles and grey literature reports were extracted.