This document summarizes research conducted by The King's Fund on volunteering in the health and care sector in England. The research aimed to understand the role, size, scope and value of volunteering as well as the impact of health reforms on volunteering. The research found that volunteers play an important role in building social capital and community resilience but that their benefits are difficult to demonstrate quantitatively. It also found that financial pressures are increasing the use of volunteers to substitute for paid staff. The document recommends developing better measures of the impact of volunteering on patient experience, outcomes and costs to more fully capture their value.