The Disarming Cartels Act directs the Department of Homeland Security to strengthen efforts to stop illegal firearms and ammunition smuggled from the United States into Mexico through the southern border. Within 90 days of the law's enactment, the Secretary of Homeland Security must increase collaboration between border and immigration enforcement agencies, establish better information sharing about seized weapons, expand investigations into crime guns recovered in Mexico to trace them back to U.S. sources, and coordinate with Mexican authorities to inspect outbound shipments more thoroughly. The bill also requires the department to develop performance measures to track the success of these anti-smuggling efforts. Starting one year after enactment and annually thereafter, the Secretary must report to Congress on the progress of these initiatives, including details about joint operations conducted and the performance metrics being used.