However, no-shows are frequent in both general medical practices and specialties, and they can be quite costly and disruptive. This problem has become more severe because of COVID-19. The primary purpose of this study is to develop machine learning algorithms to predict if patients will keep their next appointment, which would help with rescheduling appointments. The main objective in addressing the no-show problem is to reduce the false negative rate (i.e., Type II error). That occurs when the model incorrectly predicts that the patients will show up for an appointment, but they do not. Moreover, the dataset encounters an imbalance issue, and this paper addresses that issue with a new and effective hybrid sampling method: ALL K-NN and adaptive synthetic (ADASYN) yield a 0% false negative rate through machine learning models.