In the United States, many jurisdictions have enacted laws aimed at increasing naloxone availability and utilization by first responders and laypersons to combat the opioid epidemic. While there is evidence of some success of such laws in mitigating overdose deaths, the impact on donor organ availability has not been studied. We analyzed U.S. heart donors were drug intoxication was the cause of death from 2010-2017, excluding 12 states with <10 such donors. We categorized opioid antagonist laws by 5 axes: 1) any law; 2) public access; 3) bystander immunity; 4) prescriber immunity; and 5) opioid antagonist possession legalization. We conducted a population weighted difference-in-differences analysis of state-level donor rate with fixed effects for state and year. Robust confidence intervals were calculated for pooled effects across all states. A total 2,030 donors died of drug intoxication over the study period (9.9% of all donors). Adoption of opioid antagonist laws varied: 37/38 states adopted a public access policy; only 9/38 expressly legalized possession. Pooled analysis across all states showed no significant change in rate of donors for pre- vs post-implementation periods. (Figure: Effect of opioid antagonist law in states passing law vs states not passing law. Comparison is t=0, the year of passage. Robust confidence intervals are shown consistently crossing the y-axis for t>0, signaling no effect on the rate of heart donors who died of drug intoxication. Flat trendline for t<0 shows that the common-trend assumption is not violated.) CONCLUSION: Opioid antagonist policies appear to either be a small factor influencing organ availability or counterbalanced by increase in utilization. Given the rise of available donor hearts as a result of opioid-related deaths, implications of policies aimed at curtailing the opioid epidemic should be closely examined to help transplant centers and organ procurement organizations anticipate changes to the donor landscape.