Tanzania is largely an agriculture-basedeconomy. This sector accounts for over three-quarters ofnational employment, and approximately 25 percent of grossdomestic product (GDP). The national agricultural inputvoucher scheme (NAIVS) is a market smart input subsidyprogram designed in response to the sharp rise in globalgrain and fertilizer prices in 2007 and 2008. The main aimof the program is to raise maize and rice production, andthus preserve Tanzania's household and national foodsecurity. During the period from 2008 to 2013, approximatelyUnited States (U.S.) 300 million dollars has been investedin providing more than 2.5 million smallholder farmers witha 50 percent subsidy on a one acre package of maize or riceseed, and chemical fertilizer. The input subsidy programhelped Tanzanian smallholders harvest more than 2.5 milliontons of additional maize and rice grain. The NAIVS programalso faced multiple logistical challenges. These challengesare being considered in the government's new bigresults now initiative. This report summarizes the resultsof an overview of the program, and the results of two majorimpact surveys independently conducted in late 2010 and late2012. Chapter one places the NAIVS in context, reviewing thestatus of the agricultural economy and the importance ofgrain production in the country. Chapter two provides anoverview of the NAIVS program, including budget,expenditure, and implementation rules. Chapter three brieflysummarizes the impact survey results and highlights thefinancial and economic returns of the program. Chapter fourdiscusses the challenges faced during implementation of theNAIVs, and chapter five reviews the implications for furtherinvestment in this sort of input subsidy.