Limited English proficiency (LEP) is one of the most influencing factors of personal health literacy (PHL) in the older immigrant population. Over the years, the proportion of older Korean immigrants with LEP has not improved and it is still noted as a major barrier to PHL. Therefore, organizational approaches are needed to enhance the PHL of older immigrants with LEP. This study aims to find the mediating effect of social support and acculturation between LEP and PHL by conceptualizing social support and acculturation as an organizational health literacy strategy. Data from 244 older Korean immigrants living in the states of Alabama and Georgia, USA, were used to conduct the study. Korean version of the Multidimensional Scale of Perceived Social Support (MSPSS), East Asian Acculturation Measure (EAAM), and Health Literacy Survey-12 Questionnaires (HLS-Q12) were used to measure the variables. The path analysis was conducted to find the serial mediation effects of social support and acculturation. The results showed that 77.5% of the participants reported not having fluent English proficiency. English proficiency (β =− 0.21, p = 0.007), social support (β = 0.17, p = 0.004), and acculturation (β = 0.18, p = 0.011) significantly predicted the PHL, and social support (β = 0.04, p = 0.028) and acculturation (β = 0.14, p < 0.001) mediated the relationship between LEP and PHL. Discussion: Health-related organizations and communities are encouraged to provide external social support and acculturation opportunities to enhance PHL in older Korean immigrants with LEP.