To achieve the ambitious worldwide goal of reducing greenhouse gas emissions 80% or more by 2050, consumers and businesses will increasingly need to use heat pumps powered by low- or no-carbon electricity for space and water heating. But does electrification make sense for homeowners considering the switch? This report finds that replacing oil and propane furnaces, boilers, and water heaters with high-efficiency electric heat pumps can often reduce total energy use and energy bills as well as emissions. The report also summarizes studies on consumer acceptance of heat pumps and describes some early programs to promote them for space and water heating. The most successful programs provide substantial upstream incentives (to wholesalers) or midstream incentives (to contractors) and include contractor training and certification so systems are properly installed.