Abstract
• For many countries, there are limited data on the costs of running immunization services, and even less on the costs of increasing immunization coverage. • When considering different approaches for scaling up coverage, countries and funders need to understand the marginal change in coverage produced, costs of introduction, and how cost and coverage effects change depending on programmatic context. • Costing studies would benefit from improved, systematic reporting and leveraging ongoing program evaluation efforts to collect costing data. Long-term investments in the health system may allow for routine data collection and improved efficiency for budgeting and planning.