In order to fabricate high temperature sensors and other devices, it is necessary to develop ohmic contact metallizations that can withstand elevated temperatures. A variety of ohmic contact metallizations were investigated with contact resistivity measured as a function of anneal time in air. The metallizations were based on Ti and W ohmic contacts, which have contact resistivities as low as 10-4 Ω-cm2. Several of the contact metallizations were stable after 10 hrs. at 650°C, while one system, based on a Ti ohmic contact, was able to withstand > 20 hrs. at 650°C with only a 30–40% increase in contact resistivity.