Electrochemical characterization was performed on near-equiatomic nickel-titanium shape memory alloy (SMA), Al2Cr5Cu5Fe53Ni35 high entropy alloy (HEA), and UNS S31603 stainless steel to assess and compare the corrosion behavior and resistance of the material in simulated biomedical environments. A simulated bio-fluid (SBF) electrolyte was used to study the chemical and temperature-controlled parameters that the alloys experienced when they were exposed to corrosion conditions. Electrochemical testing, such as EIS and LPR tests, was performed to observe the response of the material under a range of conditions. Cyclic polarization tests were performed on all three materials to determine and compare passive to active behavior. Different performance vs. conditions correlations were described by using high-resolution surface techniques such as SEM following electrochemical testing resulting in some interfacial active-passive mechanisms.