Supplemental instruction (SI) has been shown to be effective in increasing student success in a wide variety of disciplines. Our study investigated the impact of the number of SI sessions attended on student success on exams and the effectiveness of remote SI compared to face-to-face (FTF) SI. Data were gathered for nearly 1,200 students enrolled in the first semester of a sophomore-level anatomy and physiology course at the University of Nebraska at Kearney (UNK). The number of SI sessions each student attended, if any, prior to each exam was compared to exam performance. Results for 2013-2017 demonstrated that attending even one SI session had a positive impact on exam performance, and an increase in exam performance was seen with additional SI attendance up to three sessions prior to each exam. We took advantage of the remote SI offered in the Fall of 2020, due to COVID-19, to investigate a potential effect of delivery format on SI effectiveness. There was no difference in exam performance for students attending SI FTF (2019) compared to students attending remote SI (2020), while attending SI in either format was associated with better exam scores. Our study is unique in examining the effectiveness of SI attendance at the level of individual exam performance and adds to the body of evidence that SI, whether FTF or remote, is effective in improving student success.