The IDB has 26 borrowing member countries, all of them in Latin America and the Caribbean. Together, they have a 50.02 percent of the voting power on the IDB board.
In 1999, the IDB started using a country grouping for purposes of monitoring the distribution of its lending. This criteria divides countries into Groups I and II, based on their GNP per capita in 1997.
On the basis of their lower per capita income, the Bank channels 35 percent of its lending volume to the Group II countries:Belize, Bolivia, Colombia, Costa Rica, the Dominican Republic, Ecuador, El Salvador, Guatemala, Guyana, Haiti, Honduras, Jamaica, Nicaragua, Panama, Paraguay, Peru and Suriname.
In addition to these two country groupings, the IDB has the mandate to devote at least 50 percent of its operations and 40 percent of its resources to programs that promote social equity and reduce poverty.