Partnerships and trust funds are big business for the World Bank Group. It participates in around 126 global partnership programs and administers more than 1000 trust funds which have become a significant source of revenue for the Bank Group and its clients. Partnership and trust funds offer opportunities for the Bank to benefit from partners' skills and resources, extend its reach, and innovate. Some programs and funds are complementary to the Bank or fill gaps, for example on global public goods. IEG has found that most partnership programs tackle relevant development problems and that the Bank often makes strong contributions. But there are also risks, for example proliferation of uncoordinated or competing initiatives and high transaction costs.