The Gavi Full Country Evaluations (FCE) are mixed-method, prospective evaluations in Mozambique, Uganda, and Zambia and funded by Gavi, the Vaccine Alliance. The second phase of the FCE (FCE2), was implemented from 2017 to 2018, aimed to identify drivers of vaccine coverage and equity with an emphasis on Gavi’s contribution. Evaluation results are intended to support the ongoing learning and improvement of Gavi and national immunization programs. The implementation of FCE2 was guided by a number of principles to ensure the usefulness, relevance, and quality of FCE2’s findings, and of the sustainability and transferability of the platform beyond FCE2. FCE2 was implemented by a consortium of evaluators in collaboration with the national immunization programs in each country: Health Alliance International and Universidade Eduardo Mondlane (Mozambique); Infectious Diseases Research Collaboration (Uganda); University of Zambia (Zambia); and PATH (United States).