Border Reinforcement Act of 2023 This bill requires certain actions related to border security and addresses related issues. For example, the bill requires the Department of Homeland Security (DHS) to resume all activities related to constructing a wall along the U.S.-Mexico border that were underway or planned prior to January 20, 2021; requires U.S. Customs and Border Protection (CBP) to submit a strategic five-year technology investment plan to Congress; requires CBP to maintain an active duty presence of at least 22,000 full-time equivalent Border Patrol agents by September 30, 2025; provides statutory authorization for Operation Stonegarden, a program which provides grants to law enforcement agencies involved with certain CBP operations; prohibits DHS from processing the entry of non-U.S. nationals ( aliens under federal law) arriving in between ports of entry; prohibits the Transportation Security Administration (TSA) from accepting as proof of identification certain documents, such as a warrant issued by U.S. Immigration and Customs Enforcement (ICE) or an employment authorization issued by DHS; prohibits DHS from issuing any COVID-19 vaccine mandate unless expressly authorized by Congress or taking any adverse action against an employee based solely on the employee's refusal to receive a COVID-19 vaccine; limits the use of the CBP One mobile application or a similar program to only for inspecting perishable cargo; and requires the Government Accountability Office to study and report to Congress on the costs incurred by states in support of the federal mission to secure the southwest border and the feasibility of reimbursing states for such costs.