The Sloan Digital Sky Survey (SDSS) has a rich history of releasing value-added catalogs for objects of interest to researchers, especially quasars. In that vein, we present the sixteenth quasar catalog for SDSS and the last quasar catalog for the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This new catalog of quasars, the largest to date, will include all previously identified and inspected quasars from past catalog releases and should add ~100,000 newly observed quasars detected over an area larger than 9300 deg2. Overall the catalog will contain about 750,000 unique quasars, of which ~400,000 will have been visually confirmed and inspected. In addition to presenting redshift and spectroscopic data obtained from SDSS and eBOSS, we will include multiwavelength data for many quasars from 2MASS, GALEX, UKIDSS, ROSAT, XMM, and WISE. "This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics program under Award Number DE-SC0019022. This material is also based upon work supported by the National Science Foundation under Grant No. 1616168."