Direct Air Capture (DAC) is an energy-intensive technology that removes CO2 from ambient air. Its high electricity demand risks substantial indirect emissions if powered by the grid. While policies controlling how DAC procures electricity could mitigate these emissions, their effectiveness is unclear. This study uses electricity system modeling to evaluate various electricity procurement policies. We confirm that deploying DAC without such a policy leads to significant indirect emissions, and we find that 24/7 hourly matching is the most effective policy for mitigating indirect emissions.