In this essay, we revisit Ackoff’s (1967) classic “Management Misinformation Systems” and its five myths. The paper appeared at the dawn of the information systems (IS) field and shattered popular assumptions about designing and using IS. The paper shaped the direction and scope of scholarly discourse around information systems; in contrast to dominant claims at that time, he argued that managers swam in the abundance of irrelevant information, were victims of poor modeling and, consequently, poor understanding of their own decisions, participated in destructive communication due to conflicting goals, and had a poor understanding of how systems worked. Despite the passage of 50 years (and many revolutions in information technology), researchers in the IS field still regard Ackoff’s arguments as valid and rarely debate them. Yet, given the new information-rich environments and our nearly limitless capability to collect and analyze data, we may need to reexamine these arguments to correctly frame information systems’ contemporary effects on managerial decision making. We scrutinize Ackoff’s five assumptions in light of today’s IT and data-rich environments and identify key tenets that will reframe the disciplinary discourse concerning the effects of information systems. We identify significant shifts in research on decision making including the role of abduction, data layering and options, and intelligence augmentation. We honor the extraordinary legacy of Ackoff’s remarkable paper as an IS scholar by shaping the field’s future inquiries in the spirit of the original paper.