Introduction To improve comprehension of medical care, the Joint Commission recommends that patient education materials (PEMS) be written at a fifth‐grade reading level or below. Objectives The purpose of this study was to evaluate the compliance of commonly used tertiary drug references to Joint Commission standards. Methods PEMs for the top 100 most prescribed medications in 2017 were obtained from commonly used drug information tertiary references (Lexi‐comp patient drug information, Micromedex Care Notes, Micromedex Med Essential Fact Sheets, Medline Plus, and Drugs.com) to evaluate readability. The grade reading level of each medication‐related PEM was evaluated using the Flesch‐Kincaid Grade Level test and compared with a one‐way analysis of variance using correlated samples and Tukey's post‐hoc test for significance between groups. Results The mean grade reading levels of Lexi‐comp, Micromedex Care Notes, Micromedex Med Essential Fact Sheets, Medline Plus, and Drugs.com were 4.2, 7.5, 7.8, 9.3, and 10.4, respectively. Lexi‐comp achieved a reading level at or below fifth grade for 99% of medications while Micromedex Med Essential Fact sheets was the next highest at 33%. No other reference contained drug information at or below a fifth‐grade reading level. Conclusion Lexi‐comp patient drug information consistently met the Joint Commission recommendation for medical information at or below a fifth‐grade reading level, whereas Micromedex Med Essential Fact Sheets met this recommendation approximately one‐third of the time. When providing drug information resources to patients, health‐care providers should be diligent in selecting sources that meet the Joint Commission recommendations.