Pausing Enhanced Pandemic Pathogen Research Act of 2023 This bill generally prohibits the National Institutes of Health from conducting or supporting gain-of-function research through March 30, 2028. The bill defines gain-of-function research as any research that could enhance the transmissibility, virulence, or pathogenicity of any pathogen or non-pathogen agent in a way that could lead to (1) moderate or high transmissibility, virulence, or pathogenicity in human populations; (2) significant morbidity or mortality in humans; or (3) severe threats to public health or U.S. national security. The prohibition does not apply to the characterization or testing of naturally occurring influenza virus or coronavirus unless the characterization or testing could increase viral pathogenicity or transmissibility.