S. 4645 would establish policies at the Department of Homeland Security (DHS) to help restrict the flow of illicit drugs into the United States. Specifically, it would authorize a danger-pay allowance for certain DHS employees deployed abroad. The bill also would create new criminal penalties for hindering immigration or border controls. Finally, the bill would authorize DHS to waive reimbursement from foreign governments for providing training to law enforcement personnel and impose various reporting requirements. CBO estimates that enacting S. 4645 would increase direct spending and revenues by an insignificant amount over the 2023-2032 period. CBO has not estimated the discretionary costs of implementing the bill. The bill contains no intergovernmental or private-sector mandates as defined in the Unfunded Mandates Reform Act.