- South Mississippi Electric Power Association (SMEPA) is a generating and transmission cooperative based in Hattiesburg, MS. SMEPA serves over 390,000 members through its 11 member distribution systems, including Singing River Electric Power Association. Singing River Electric purchases all wholesale power from SMEPA.
- Electric Power Associations of Mississippi (EPAs of Mississippi) represent 26 electric power associations in the state, which deliver electricity to 1.7 million Mississippians. The statewide trade organization assists co-ops with issues involving safety, training, communications (including publishing the Today in Mississippi"), and legislative matters; as well as coordinates the annual Youth Leadership Program and assistance for co-ops during natural disasters.
- National Rural Electric Cooperative Association (NRECA) is the national service organization dedicated to representing the national interests of cooperative electric utilities and the consumers they serve.
- Touchstone Energy is a national alliance of 641 local, consumer-owned electric cooperatives providing high standards of service with integrity, accountability, innovation and a long-standing commitment to community.