The accelerated use of technologies has led to what is termed the fourth industrial revolution, or Industry 4.0. It is based on machinery, robots, production lines, items and operators connected via the Internet to each other and to back-end systems, as a part of the Internet of Things (IoT). In this paper, we propose a new IoT Technological Maturity Assessment Scorecard that can assist manufacturers in adopting IoT-technologies. To demonstrate the Scorecard, we present a case study applying the scorecard in four Norwegian manufacturing companies.