The aging of thermal spray (TS) cathodic protection (CP) anodes is usually characterized by the amount of current passing through the anode-concrete interface. This charge, also called electrochemical age, can be correlated to bond strength and eventual failure of TS Zn anodes. Several non-destructive techniques were subsequently applied to aged thermal spray anodes to determine if other property measurements would correlate to electrochemical age and thus to service life. The techniques considered are the circuit resistance of impressed current anodes, the AC resistivity between the rebar and the anode, and the surface resistivity of the T S anodes. All three techniques gave a good correlation of measured property to electrochemical age. Surface resistivity can also be used to calculate the thickness of anode remaining. Keywords: thermal spray, cathodic protection, nondestructive evaluation, electrochemical age, circuit resistance, AC resistance, surface resistivity, Zn, Zn-Al, Zn hydrogel, Al-Zn-In.