Health and Environmental Funders Network is a left-of-center network that mobilizes philanthropic activities related to environmentalist concerns. 
From its founding in 1999 to 2009, Health and Environmental Funders Network worked on campaigns related to toxics and antibiotic resistance and issues related to race and gender. It also worked on responses to communities affected by Hurricanes Katrina and Rita. From 2010 to 2015, the network disseminated information and action on various environmental issues. The network was also involved in the philanthropic response to the 2010 Deepwater Horizon oil spill, the water contamination in Flint, Michigan, and the 2014 West Virginia chemical spill. In 2019, Lead Funders Action Network, a philanthropic investment campaign focused on lead remediation, came under HEFN’s umbrella.  
Health and Environmental Funders Network has a group of various organizations that have made important contributions called the HEFN Member Foundations. They include the Charles Stewart Mott Foundation,  a grant maker that funds organizations and communities in the subject areas of education, the environment, local issues related to Flint, Michigan and civil society. 
Another HEFN Member Foundation is the Liberty Hill Foundation,  founded in 1976 by Anne Wendel, Win McCormack, Sarah Pillsbury, and Larry Janss to promote left-of-center ”social change” in Los Angeles County, California. 
Ansje Miller is the executive director of the Health and Environmental Funders Network. Before joining HEFN, Miller was the director of policy and partnerships for the Center for Environmental Health (CEH), where she directed the activities in the Eastern States Office and represented the CEH to various important figures. She also founded and directed the Environmental Justice and Climate Change Initiative, worked in leadership roles, and served as board chair for various organizations such as the Cancer Free Economy Network, BizNGO Working Group on Safer Chemicals & Sustainable Materials, Sierra Club National, and the Reproductive Health Technologies Project. She has been involved in the Green Chemistry Initiative, California’s global warming law, and the 2016 update to the Toxic Substances Control Act.