Since 2007, the Development Innovations Group (DIG) has expanded and improved access to clean water, sanitation and hygiene (WASH) for informal settlers in poor, urban and peri-urban communities worldwide. To improve service delivery to informal settlements, DIG works with and ensures buy-in from the full range of stakeholders, including municipal governments, WASH utilities, WASH small service providers (SSPs), donors, and households. In this vein, DIG has developed baseline surveys to help utilities understand the demand and capacity to pay for water and sanitation services in informal settlements, which has proven to utilities that the poor are a viable market for basic service delivery. DIG has also worked with utilities and SSPs to develop business plans, ensuring the financial viability of providing WASH services in informal settlements. Additionally, DIG has worked with banks to establish cash-flow based loan products that allow for utilities to borrow from banks in order to launch WASH projects in informal settlements. Importantly, DIG works with governments to ensure buy-in for the projects and multi-lateral institutions to guarantee that the utilities and SSPs can benefit from any subsidies (such as output-based aid) related to these projects. At the household and SSP levels, DIG has delivered training on basic operations and maintenance (O&M) of water connections and developed “save-to-pay” mechanisms to ensure households can maintain access to WASH services. DIG’s WASH programming has had and continues to have a prolonged, meaningful, and sustained positive impact on the lives of the poor around the world.