Protecting America's Food and Agriculture Act of 2019 This bill authorizes U.S. Customs and Border Protection (CBP), every fiscal year, to hire, train, and assign 240 new agricultural specialists until the total number of specialists equals and sustains the requirements identified each year in the Agriculture Resource Allocation Model. The CBP may also hire, train, and assign support staff to assist the specialists and specified levels of agricultural canine teams. In calculating the number of specialists needed at each port of entry through the Agriculture Resource Allocation Model, the Office of Field Operations of the CBP must (1) rely on data collected regarding the inspections and other activities conducted at each such port of entry; and (2) consider volume from seasonal surges, other projected changes in commercial and passenger volumes, the most current commercial forecasts, and other relevant information. The Government Accountability Office (GAO) must conduct a review of the efforts of the Department of Homeland Security, the Department of Agriculture, and other federal agencies to address risks to the agricultural supply. The GAO must analyze (1) interagency coordination and the distribution of responsibilities among federal agencies with respect to the inspection of agricultural commodities entering the United States; (2) the effectiveness of such inspection responsibilities among federal agencies; and (3) the training provided to, and working conditions of, CBP Agriculture Specialists.