Most of the world’s poor no longer live in low-income countries. An estimated 960 million poor people—a new bottom billion—live in middle-income countries, a result of the graduation of several populous countries from low-income status. That is good news, but it has repercussions. Donors will have to change the way they think about poverty alleviation. They should design development aid to benefit poor people, not just poor countries, keep supporting middle-income countries, think beyond traditional aid to craft coherent development policies, and work to help create space for more inclusive policy processes in new and old MICs.