Although numerous government, nonprofit, and relief organizations have endeavored to educate and prepare the American public for disasters, adults with physical, mental, and educational disabilities remain among the most vulnerable and least prepared subgroups of the population. The lack of alignment between the literacy demands of existing disaster preparedness and recovery materials and the literacy skills of many vulnerable subgroups limits their ability to understand and effectively use potentially life-saving information. We review the literature on literacy and vulnerable populations, propose a new model for disaster literacy, and describe opportunities for incorporating best practices into planning and preparedness activities. Disaster literacy is defined here as an individual's ability to read, understand, and use information to make informed decisions and follow instructions in the context of mitigating, preparing, responding, and recovering from a disaster. Recommendations are made for developing and evaluating disaster communication materials for vulnerable populations. To meet and improve the disaster literacy of vulnerable populations we suggest pilot-testing and evaluation be routinely used to inform selection of media type, message, and point of contact.