CatWISE is a NASA ADAP funded project to combine WISE and NEOWISE survey data at 3.4 and 4.6μm (W1 and W2) collected from 2010 to 2016. This dataset represents four times as many exposures and spans over ten times as large a time baseline as that used for the AllWISE catalog. The Preliminary CatWISE catalog consists of 957,285,574 sources over the entire sky, and includes the measured motion of sources over the 6 year span of the data. In this talk I will review the processing steps leading to the generation of the catalog, and I will summarize its main characteristics. I will then showcase the first results from our search for the coldest brown dwarfs in the solar neighborhood, part of a larger effort to answer one of the most fundamental questions in all of astrophysics: how, and with what efficiency, can star formation create objects of extremely low mass?