Background: During the COVID-19 pandemic, the United States' Centers for Disease Control and Prevention (CDC) created guidance documents that were too complex to be read and understood by the majority of adults with intellectual and developmental disabilities who often read at or below a third-grade reading level. This study explored the extent to which these adults could read and understand CDC documents simplified using Minimised Text Complexity Guidelines. Method: This study involved 20 participants, 18-48 years of age. Participants read texts and responded to multiple-choice items and open-ended questions to gather information about how they interacted with and understood the texts. Results: The results provide initial evidence that the Minimised Text Complexity Guidelines resulted in texts that participants could read and understand. Conclusion: Implications for increasing the accessibility of public health information so that it can be read and understood by adults with extremely low literacy skills are discussed.