The Ozone Mapping and Profiler Suite (OMPS) on the National Oceanic and Atmospheric Administration Suomi National Polar-Orbiting Partnership spacecraft has completed three more years of orbital operation since the OMPS opened its nadir door for the scene data collection on January 26, 2012. The sensors’ spectral channels have been calibrated in-flight by a working solar diffuser and a reference solar diffuser. The instruments’ optical degradation is determined through the changes in the instruments’ throughput via orbital solar observations. The observed degradation at the shortest wavelengths is for the sensor optics, and in excess of 2% for the OMPS working solar diffuser. The absolute irradiance calibration uncertainties meet the system requirement of 7% for most of the channels. Unexpected orbital wavelength variation in sensor scan direction is evidenced to cause about 2.6% error, not compliant with a 2% allocation and so some margin will be needed to accommodate the exceedance.