Abstract: The present invention provides biodegradable, biocompatible bis-(?-amino acyl)-diol-diester-containing poly(ester amide) (PEA) and poly(ester urethane) (PEUR) co-polymer compositions with mechanical properties that can be readily tailored by selection of various combinations and proportions of the building blocks of the co-polymers. The compositions are suitable for use in production of drug-releasing biodegradable particles and implantable surgical devices, such as stents and internal fixation devices. The co-polymer compositions, particles and surgical devices biodegrade in vivo by enzymatic action to release bioactive agents in a controlled manner over time as well as biocompatible breakdown products, including one to multiple different amino acids.