Human monoclonal antibodies that specifically bind to TNFSF13b polypeptides are disclosed. These antibodies have high affinity for hTNFSF13b (e.g., KD=10−8 M or less), a slow off rate for TNFSF13b dissociation (e.g., Koff=10−3 sec−1 or less) and neutralize TNFSF13b activity in vitro and in vivo. The antibodies of the invention are useful in one embodiment for inhibiting TNFSF13b activity in a human subject suffering from a disorder in which hTNFSF13b activity is detrimental. Nucleic acids encoding the antibodies of the present invention, as well as, vectors and host cells for expressing them are also encompassed by the invention.