Medication costs make up over 10% of health care dollars and are the fastest growing source of medical expense. Many state and federal officials have called for action that would add cost transparency to the complex, opaque medication supply chain believing that this will lead to lower prices and higher value care. Though this may appeal to our intuition, evidence that medication cost transparency leads to higher value care is scant. In order to add to the evidence base, four other investigators and I embarked on a 9-month investigation designing and evaluating the effect of medication cost transparency decision support built into the electronic health record. Bottom line: it makes a difference. The results were recently published and are available on the JAMIA website: https://academic.oup.com/jamia/advance-article-abstract/doi/10.1093/jamia/ocz025/5445905.