K-band radio observations have the potential to form the basis for the most accurate celestial reference frame ever constructed.Relative to the standard S/X observing bands,at K-band sources are expected to exhibit reduced source morphology and reduced core-shift.This reduction in astrophysical systematics should allow for a more stable reference frame at K-band,but should also be advantageous in tying the VLBI radio frame to the Gaia optical frame.