While the International Bank for Reconstruction and Development (IBRD) raises most of its funds on the world's financial markets, IDA is funded largely by contributions from the governments of its richer member countries. Additional funds come from IBRD's and International Finance Corporation's (IFC) income and from borrowers' repayments of earlier IDA credits.

Partners meet every three years to replenish IDA funds and review IDA’s policies. The most recent replenishment of IDA’s resources, the seventeenth (IDA17), was finalized in December 2013, resulting in a record replenishment size of Special Drawing Rights (SDR) 53.5 billion ($75 billion) to finance projects over the three-year period from July 1, 2017 to June 30, 2020.

This amount includes partner grant contributions, reflows from credit repayments, World Bank Group transfers, and concessional partner loans. Partner contributions amounted to SDR 16.5 billion ($23.1 billion). In addition, partners provided SDR 2.8 billion ($3.9 billion) in concessional partner loans, and contributions for the Multilateral Debt Relief Initiative (MDRI) of SDR 2.9 billion ($4.1 billion), to cover IDA's debt relief costs. Internal resources from credit repayments and transfers from IBRD and IFC, amounted to SDR 15.5 billion ($21.7 billion). Funding borrowed from the capital market will support the commitments in the amount of SDR 15.9 billion ($22.3 billion).

To increase openness and help ensure that IDA’s policies are responsive to country needs and circumstances, representatives of borrower countries from each IDA region have been invited to take part in the replenishment negotiations since IDA13. In addition, since IDA13 background policy papers are publicly released, as well as drafts of the replenishment reports before their finalization.