Nearly half of older people cannot easily walk 400 meters. Powered mobility aids such as seated scooters discourage healthful walking and have limitations due to size and cost. Using human-centered design, we have developed a novel power assisted walker (PAW), which can be used as a manual walker or as a standing electric scooter. A user can push the device manually supported by a four-wheeled walker or step onto a footplate and ride it as a three wheeled standing scooter, with safety enhanced by two anti-tip casters. A working prototype has demonstrated the feasibility of this design. It also meets user-defined requirements for safety, usability, and transportability. Designs for additional prototypes overcome several engineering challenges and will enable a wide variety of users to meet their mobility needs in the community.