A coating and method for a coating an implantable device or prostheses are disclosed. The coating includes an undercoat of polymeric material containing an amount of biologically active material, particularly heparin, dispersed therein. The coating further includes a topcoat which covers less than the entire surface of the undercoat and wherein the topcoat comprises a polymeric material substantially free of pores and porosigens. The polymeric material of the topcoat can be a biostable, biocompatible material which provides long term non-thrombogenicity to the device portion during and after release of the biologically active material.