H.R. 4517 would require the Departments of Defense and State to explore the feasibility of reimbursing U.S. citizens, nationals, or lawful permanent residents who expended personal funds to evacuate other U.S. citizens, lawful permanent residents, or Afghan allies from Afghanistan over an eight-month period beginning on August 1, 2021. The agencies would be required to submit that study to the Congress within 180 days of enactment. Using information about the costs of preparing similar studies, CBO estimates that implementing the bill would cost less than $500,000 over the 2023-2028 period. Any spending would be subject to the availability of appropriated funds.