The Plains CO2 Reduction (PCOR) Partnership performed a wellbore integrity assessment of wells penetrating the basal Cambrian system in the United States. The ability of the system to retain injected CO2 over an extended period of time is, in part, dependent on the integrity of wellbores that penetrate the target reservoir. This study's evaluation of wellbore integrity involves analyzing wellbore characteristics to derive a relative leakage potential score. The results of this evaluation determined that 15% of the wells assessed were classified as having moderate or higher potential for deep well leakage.