Small businesses contribute to the U.S. economy by bringing growth and innovation and by being more adaptable to changes in the economy. Although extensive research has been done on small businesses—sometimes defined as fewer than 250 or 500 employees—very little is known about microbusinesses, businesses with one to four employees. This InfoBrief provides new information on microbusinesses and their research and development activities, strategies, and drivers of competitiveness. Data are from the Microbusiness R&D and Innovation Survey, developed and cosponsored by the National Center for Science and Engineering Statistics within the National Science Foundation and by the U.S. Census Bureau.