The electrochemical oxidative coupling of methane (E-OCM) to higher hydrocarbons, requires anodes that are stable under reducing conditions. We have previously demonstrated high activity with long term stability/durability for the perovskite anode BaMg0.33Nb0.67-xFexO3-δ (BMNF) while performing E-OCM1. Our group has also improved the total conductivity and activity of barium niobate perovskites via exchange of Mg for Ca (from 18 mS/cm-1 to 41 mS/cm-1), while also decreasing the Goldschmidt tolerance factor below 1 for increased cubic perovskite structural stability2. Perovskite metal oxide thin films can be produced with well-defined thicknesses and stoichiometries through pulsed laser deposition (PLD)3. These thin films are utilized in cyclic voltammetry experiments on YSZ substrates to further elucidate the chemical stability and oxygen sub-stoichiometry of high temperature SOFC/SOEC electrodes. Through application of reducing potentials to the electrode of interest, the voltage and current responses can be correlated to effective oxygen activities in which reduction of the electrode may occur. Usage of this technique with calcium and iron doped barium niobate perovskites (BaCa0.33Nb0.67-xFexO3-δ - BCNF) provides insights into the thermochemical stability and iron doping effects under highly reducing environments. The BCNF thin film electrodes were characterized via grazing incidence XRD and XRF for crystal structure and chemical composition. After initial characterization, cyclic voltammetry experiments were performed in a novel cell setup. These BCNF thin films show promise for evaluating stability mechanisms for E-OCM operation while providing details on compositional changes and oxygen loss of BCNF in reducing environments.