For four decades U.S. foundations have had the ability to make below-market-rate investments in activities consistent with their missions, and count these investments as part of their annual charitable distributions. Program-related investments, or PRIs, provide the opportunity for a philanthropic multiplier effect, as foundations invest the dollars repaid from earlier PRIs into new charitable investments. The limited use of program-related investments by foundations largely reflects a number of factors including the limited number of non-profit organizations with the experience and capacity to manage financial investments, the lack of a predictable income stream to needed for repayment, limited proficiency in the use of investment tools among foundation staff, and/or reliance by foundations on more traditional approaches to philanthropy. In spite of these challenges, the use of PRIs among small to mid-sized foundations, including community foundations, as well as the breadth of areas to which PRIs are being applied is expanding. While the development of low-cost housing and community development programs domestically, as well as microfinance initiatives internationally, have historically attracted PRIs, there is greater use of this instrument in such areas as education, arts and culture, social and health programs, and environmental sustainability. The analysis presented in this paper documents the who, what, and where of recent foundation PRI activity for those interested in learning more about this unique philanthropic tool. (Contains 5 figures, 8 tables, and 6 endnotes.)