Preparing for the Next Pandemic Act This bill provides funding to the Biomedical Advanced Research and Development Authority (BARDA) for activities to expand domestic manufacturing of medical countermeasures and to the Office of the Assistant Secretary for Preparedness and Response for grants to establish state stockpiles of medical supplies for use during public health emergencies. These funds are designated as an emergency requirement, which exempts them from discretionary spending limits and other budget enforcement rules. The bill also makes other changes to BARDA's authorities and duties with respect to countermeasures and the administration of the Strategic National Stockpile.