The Institute receives grants from a number of sources to cover the costs associated with its policy work and to provide a wide variety of deliverables.

Most of this funding for particular programs comes from foundations, although federal contract funds are also part of the equation. The 18 states of the region also contribute to the Institute, and the members of the Institute's Regional Leadership Council also contribute to and raise funds to support the organization.

A partial list of supporting foundations includes:

• The Great Lakes Protection Fund
  For invasive species and the cleanup of contaminated sites
• The Joyce Foundation
  For the Great Lakes Basin
• The Keith Campbell Foundation
  For the Chesapeake Bay
• The W.K. Kellogg Foundation
  For food and agriculture
• The McKnight Foundation
  For the Upper Mississippi River
• The C.S. Mott Foundation
  For the Great Lakes Basin
• The William Penn Foundation
  For watersheds in the Delaware River Basin
• The Surdna Foundation
  For revitalizing older industrial cities
• The Town Creek Foundation
  For the Chesapeake Bay
• Winrock International
  For Farmers' Markets
• The Rockefeller Foundation
  For Transportation Policy