Multiple U.S. cities and one state — all of which have active energy efficiency programs — have recently adopted mandatory building performance standards (BPS) that require existing commercial buildings (and often multifamily buildings) to meet energy benchmarks. We interviewed BPS program administrators, utility and other energy efficiency program administrators, other experts and some state utility regulators for their views on the role of efficiency programs in BPS implementation. Based on this work, we conclude that energy efficiency programs are critical to help jurisdictions implement BPS because they can educate building owners and provide financial and technical assistance. We discuss the role of energy efficiency programs before and after BPS take effect, including approaches to crediting them for the energy savings they achieve during these two different periods.