  The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE)
spacecraft has been conducting a two-band thermal infrared survey to detect and
characterize asteroids and comets since its reactivation in Dec 2013. Using the
observations collected during the fourth and fifth years of the survey, our
automated pipeline detected candidate moving objects which were verified and
reported to the Minor Planet Center. Using these detections, we perform thermal
modeling of each object from the near-Earth object and Main Belt asteroid
populations to constrain their sizes. We present thermal model fits of asteroid
diameters for 189 NEOs and 5831 MBAs detected during the fourth year of the
survey, and 185 NEOs and 5776 MBAs from the fifth year. To date, the NEOWISE
Reactivation survey has provided thermal model characterization for 957 unique
NEOs. Including all phases of the original WISE survey brings the total to 1473
unique NEOs that have been characterized between 2010 and the present.
