Association of Science-Technology Centers (ASTC), found here
Center for Advancement of Informal Science Education (CAISE), found here.
Citizen Science Association, found here
Citizen Science Central at Cornell Lab or Ornithology, found here
Institute of Museum and Library Services (IMLS), found here
KQED, found here
National Center for Science and Civic Engagement (NCSCE), found here
Science Education for New Civic Engagements and Responsibilities (SENCER), found here