On GOES 16–19, the primary instrument for measuring solar- and galactic-origin energetic protons is the Solar and Galactic Proton Sensor (SGPS). Each satellite carries two SGPSs, one looking eastward and one looking westward in; the orbit. Each SGPS measures proton fluxes in 13 differential energy channels spanning approximately 1–500 MeV and a single >500 MeV integral channel. This paper focuses on the characterization of the two SGPS channels that ; overlap with the >300 MeV to >433 MeV proton energy response of neutron monitors in the polar regions. Although the SGPS differential channels are primarily aimed at measuring solar energetic particle (SEP) fluxes, the P11 ; (>500 MeV) integral channel was designed to measure both galactic cosmic rays (GCRs) and the high energy component of SEP events. The P10 (275–500 MeV) channel also measures both GCRs and SEPs. Special care is needed in ; processing the P10 and P11 channels to obtain an accurate spectrum at energies >300 MeV. A bowtie analysis of the response functions using realistic SEP and GCR spectra gives different geometric factors and effective ; energies for the two populations.