The Advanced Technology Microwave Sounder (ATMS) on board Suomi NPP is a 22 channel microwave sounder that provides continuous cross-track scanning in an 824 km sun-synchronous orbit. The reprocessed (versions RP1 & RP2) Sensor Data Records (SDR) from ATMS provide Level 1b calibrated and geolocated radiance data produced from the ATMS Raw Data Record (RDR) and Temperature Data Record (TDR). The reprocessing generated consistent Level-1b SDRs using unified and consistent calibration algorithms that removed artificial jumps in data caused by operational changes, instrument anomalies, contamination from anomaly views of the environment or spacecraft, and other causes. ATMS reprocessed version 1 (RP1) data was generated using a fixed calibration algorithm derived from the March 2017 operational calibration. The RP1 algorithm was run for the time period covering 9 Nov 2011 to 8 March 2017. ATMS reprocessed version 2 (RP2) data was generated using a fixed calibration algorithm derived from the October 2019 operational calibration. The RP2 algorithm was run for the time period covering 9 Nov 2011 to 15 October 2019. ATMS SDR data obtained from the NOAA Comprehensive Large Array-Data Stewardship System (CLASS) are distributed as aggregated 8 minute files consisting of 15 granules in the Hierarchical Data Format v.5 (HDF5) with metadata attributes included.