Abstract: In various embodiments, the present invention provides a functionalized thermoplastic polyurethane (TPU) containing bulk incorporated or surface-grafted quaternary ammonium compounds (QAC)s for contact-killing of a variety of microbes, where the QACs are on the surface of TPU to provide a sterile surface material that prevents bacteria commonly involved in device-associated infections (DAIs) from proliferating. The functionalized TPUs of the present invention can be formed into a wide variety of 3-dimensional shapes, such as catheters, medical tubing, laryngeal or tracheal stents, sutures, prosthetics, wound dressings, and/or a coating for medical devices and contains the residue of either a QAC containing diol monomer or an alkene functional diol monomer, which then allows the TPU to be functionalized with a QAC containing disulfide or free thiol compound, to form a quaternary ammonium functionalized thermoplastic polyurethane compound having antimicrobial properties for use in medical devices.