Metal corrosion is a significant problem for the US concrete infrastructure. Accurate and continuous corrosion sensing methods would help reduce this cost and enable effective health monitoring and service life prediction. In this paper, recent efforts to apply giant magneto-resistive response (GMR) and eddy current sensors for corrosion sensing are described. The sensors are applied in passive and active sensing configurations, neither of which require excavation of the concrete, so remote sensing at a surface and internal sensing with an embedded unit are possible. The passive and active testing configurations are described. Then experimental results for aluminum corrosion are presented, with the aim of identifying existing corrosion state to date and rate of active corrosion at time of sensing.