Background: San Diego County's prescription drug related deaths have been on the rise following the nationwide trends. In January 2014, under the provisions of the Affordable Care Act (ACA), along with the enactment of the Medicaid Expansion, an individual mandate for health insurance went into effect. As a result, public health coverage has increased leading to changes in the patient payer mix. This study explores the changing trends in payer source as they relate to overdose emergency department discharges (EDD) in San Diego County with regards to the ACA implementation. Methods: The 2010-2014 Office of Statewide Health Planning and Development (OSHPD) EDD database was examined by intention of overdose and expected payer source. Data were then stratified by year and correlated with ACA implementation time points to identify trends pre and post ACA enactment. Results: From 2010 through 2014, there were 18,345 EDD among San Diego County residents for overdose, for which 62.27% of these were unintentional. The overall mean age of patients was 33.7 years, with more visits made by females (57.8%). A strong heterogeneity between the intention of overdose and the types expected payer source for the patient was observed: χ2 (3) = 154.00, p = .000. Conclusions: There is a relationship between intent of overdose in emergency department discharges and payer source. Due to the increased number of public coverage recipients and the fact that expected payer source is associated with the intent of overdose, prevention programs can be targeted through public programs.