Cognitive biases can lead to diagnostic errors, and reflective reasoning has been promoted to enhance diagnostic accuracy. This study of internal medicine trainees examined whether prior exposure to media-distributed disease information would influence subsequent diagnostic accuracy and found that similarities between prior reading and case descriptions contributed to diagnostic inaccuracy, highlighting the importance of availability bias. The participants were then asked to return to the cases, reflect on their previous diagnosis, and consider alternate diagnoses. This extended reflection process led to improvements in diagnostic accuracy, consistent with earlier reflective reasoning studies. An accompanying editorial recommends encouraging reflection and explaining its benefits when teaching diagnostic thinking.