Current Celestial Reference Frame Status at X/S and K Bands

The third realization of the International Celestial Reference Frame, ICRF3, was finalized in June 2018 using VLBI sessions through March 2018. It was accepted by the IAU in August 2018 and became official on Jan. 1, 2019. ICRF3 contains 4536 sources in its X/S catalog and 824 sources in its K band catalog. In the 4 years since the finalization of ICRF3, dedicated astrometric campaigns have been made to maintain, improve and expand the ICRF at X/S and K bands and now four additional years of observations are available. In the northern hemisphere, these campaigns have used the VLBA at both X/S and K bands under the USNO’s VLBA time share allocation. And in the southern hemisphere, the HARTRAO-HOBART26 network has been used at K band. These sessions, as well as the IVS sessions, have added ~20% more sources to the X/S catalog and ~25% more sources to the K band catalog, along with significant reductions in the scaled formal errors. We will present the current state of the X/S and K band CRF catalogs, including the distribution of sources and observations and improvements in the scaled formal errors.