We assessed the effectiveness of an adaptive online learning system for student learning and outcomes in undergraduate anatomy and physiology courses. Across six institutions of higher education, we compared improvement on posttests relative to pretests, grade distributions and retention between treatment sections using LearnSmart, an adaptive learning system developed by McGraw Hill Higher Education (MHHE), and control sections given questions online from an MHHE test bank. Overall, we found no significant improvement in any metric between sections using LearnSmart and those given online questions. There were significant differences among schools, with two of the six schools showing consistently better results in the treatment sections relative to the controls. We could not identify any particular differences between these schools and those not showing improvement. We speculate that this adaptive learning system may perform best when course goals are closely aligned with texts and the adaptive learning system.