Despite its proven better corrosion-resistant properties and higher critical chloride threshold than conventional carbon steel reinforcing bar (rebar), the high cost of stainless steel (SS) continues to be a barrier against its widespread use for reinforcing concrete structures exposed to marine and de-icing agents. With existing and emerging cost-effective but less corrosion-resistant or ‘unproven’ rebar alternatives, there exists a need to develop less costly SS rebar grades to encourage its widespread application. This development must begin with justification for the incorporation of the expensive alloying components in SS rebar, notably molybdenum and nickel that are rich in traditional austenitic and duplex grades like 316LN and 2205, respectively. Current results have shown that molybdenum-free austenitic 304L and duplex 2304 rebar counterparts provide sufficient corrosion resistance in chloride-contaminated concrete structures. Also, manganese, used to replace nickel in austenitic 24100 or duplex 2101, did not provide sufficient corrosion resistance as their nickel-containing 304L counterpart. The role of molybdenum, nickel and manganese in enhancing passive film and corrosion-resistant properties is discussed.