The present disclosure provides activatable binding polypeptides (ABPs), which contain a target binding moiety (TBM), a masking moiety (MM), and a cleavable moiety (CM). The present disclosure provides activatable antibody compositions, which contain a TBM containing an antigen binding domain (ABD), a MM and a CM. Furthermore the present disclosure also provides ABPs which contain a first TBM, a second TBM and a CM. The ABPs exhibit an "activatable" conformation such that at least one of the TMBs is less accessible to target when uncleaved than after cleavage of the CM in the presence of a cleaving agent capable of cleaving the CM. The disclosure further provides libraries of candidate ABPs, methods of screening to identify such ABPs, and methods of use. The disclosure further provides ABPs having TBMs that bind VEGF, CTLA-4, or VCAM, ABPs having a first TBM that binds VEGF and a second TBM that binds FGF, as well as compositions and methods of use.
