The 2012-2013 budget estimate for core costs, planned supplementary immunization activities and emergency response is US$ 2.19 billion, against which there is a funding gap of US$ 945 million (US$ 270 million for 2012). The Initiative is tracking US$ 344 million in firm prospects; if donors fulfill these commitments, then the overall funding gap for 2012-2013 is reduced to US$ 601 million. The most pressing requirement is for flexible multi-year funding.

The budget estimate of US$ 2.19 billion represents a decrease of US$ 44 million compared to earlier estimates, driven primarily by the cancellation or reduction of supplementary immunization activities (SIAs) in 24 high risk polio-free countries across west, central and the Horn of Africa as well as Central Asia in the first half of 2012. Additional cuts in SIAs will have to be instituted in the second half of 2012 should the required funding not be available. The revised budget estimate does include an increase in surge capacity, primarily for Nigeria. New contributions of US$ 98 million for 2012-2013, received since February 2012 from Angola, Bangladesh, Bill & Melinda Gates Foundation, Canada, Japan and Nigeria help to offset this increase.