Applying the Zwicknagl, Zevin, and Fulde (ZZF) approximation for the spectral densities of the occupied and empty {ital f} states resulting from a degenerate-Anderson-impurity model, which incorporates crystal fields, we compute the low-temperature magnetic susceptibility of YbN. The model, in which each crystal-field level couples to the band states with its own hybridization function, has previously been successfully applied without the ZZF approximation to explain the specific-heat structure at low temperatures. The ZZF approximation removes the spurious zero-temperature behavior of the parent noncrossing approximation for the susceptibility. Surprisingly, even at the low crystal-field degeneracy ({ital N}=2) of YbN, the Shiba relation is very nearly satisfied. The appropriate experimental impurity susceptibility for comparison is extracted from the measurement by removing an empirical exchange interaction. The resultant Kondo temperature ({ital T}{sub 0}=8.49 K) is consistent with previous specific-heat estimates (10--11 K), and the agreement with experiment is good.