The benefits of energy efficiency extend beyond energy savings. Homes, commercial buildings, and industrial facilities gain comfort, health, and safety benefits from energy efficiency programs. Additional benefits for businesses include savings on maintenance, materials, and the costs of regulatory compliance. On the supply side, electric utilities enjoy reduced system costs. Focusing on the residential, business, and utility sectors, this report examines each of these multiple benefits, their role in program marketing, and current best practices for including them in cost-effectiveness testing.