Innovators to Entrepreneurs Act of 2019 This bill expands eligibility for the Innovation Corps (I-Corps) program and requires development of an I-Corps course to support commercialization-ready participants. The bill requires the National Science Foundation (NSF) to allow grantees of the Small Business Innovation Research (SBIR) Program and other entities to participate in I-Corps courses. The cost of participation by such a grantee in a course may be furnished through I-Corps Teams grants, through funds awarded to grantees under the SBIR Program or the Small Business Technology Transfer (STTR) Program, by the grantor federal agency using funds set aside for the SBIR and STTR Programs, or by the participating teams. The NSF shall develop an I-Corps course, to be offered by I-Corps regional nodes, to support commercialization-ready participants. The course shall support participants that have completed an I-Corps course and participants that have made the decision to market an innovation. The Government Accountability Office shall report on the I-Corps Program, including by assessing the effects of the I-Corps on the commercialization of federally funded research and development, the higher education system, regional economies, and the national economy.