The use of titanium shape memory alloy Ti-18Zr-15Nb with promising coatings for the manufacture of medical implants is considered. In this paper, we examined plasma electrolytic oxidation (PEO) in a pulsed bipolar mode with different frequencies to protect the surface from the aggressive environment of the human body.. Two frequencies of 300 and 1000 Hz were used. The results of SEM, EDS, XRD analysis, and electrochemical tests of the coatings were discussed. As a result of comparison, it was shown that carrying out the PEO process at 1000 Hz provides the formation of a more uniform coating with higher quality than the coating obtained at 300 Hz.