Background: Written stroke patient education materials are instrumental to improving the patient care experience. Since 2010, national certifying bodies recommend written materials at a maximum reading level of 5th grade to meet health literacy needs. In 2016 certified comprehensive and primary stroke centers from a multi-state health system discovered significant variation among stroke patient education booklets (SPEB) developed by separate facilities/states, and in 2018 implemented a standard SPEB by partnering with an external organization (EO). The health system worked with the EO to add information in the SPEB specific to carotid disease and stroke symptoms. Purpose: Compare the health literacy of pre-standardization SPEBs to the updated EO SPEB with and without carotid education. Methods: Readability assessments were used to determine reading grade levels for pre-standardization SPEBs consisting of 7 SPEB among 18 facilities in 5 states, the EO standardized SPEB with and without the additional carotid education, and the carotid education additions alone. Assessments included: 1) Flesch Reading Ease Formula, 2) Flesch-Kincaid Grade Level, 3) Gunning Fog Index Readability Formula, 4) Simple Measure of Gobbledygook (SMOG) Readability Formula, 5) Coleman-Liau Index, 6) Automated Readability Index, and 7) Linsear Write Formula. These assessments were then used to calculate a readability consensus score (RCS), reported as grade levels, using an online tool. Visual Imagery was not included in the assessments. Results: The range of RCS grade levels for pre-standardization materials was 7th to 12th grade. A grade level of 11 - 12 was found for 57.1% of sites. The EO SPEB without carotid education had an RCS grade level of 7 and with the additional information had a grade 8 level. The carotid education alone was at a college graduate level. Utilization of the EO SPEB decreased the health literacy level for 88.9% of sites. Conclusion: A standardized SPEB was implemented for a large five state health system. The health literacy level significantly improved at almost 90% of the participating facilities. The recommended 5 th grade health literacy level was not achieved based on the RCS. More research is needed on the impact visual imagery has on health literacy.