Idaho National Laboratory (INL) has a well-established capability for performance testing of solid-oxide cells and stacks, operating in the electrolysis mode for efficient hydrogen production from steam. Capabilities range from fundamental characterization of button cells [1] and single cells to multi-kW testing of large stack configurations [2]. On-line diagnostic capabilities include electrochemical impedance spectroscopy, sweep and cyclic voltammetry, reversible operation with power supplies and electronic loads, plus a wide range of supporting instrumentation and hardware. The INL high-temperature laboratory includes seven test stands for small-scale to multi-kW testing, including a high-pressure test stand. INL also has a significant array of advanced solid oxide electrolysis cell (SOEC) post-test examination capabilities, including SEM/EDS, Auger electron spectroscopy, Raman spectroscopy, CT scan, Local Electrode Atom Probe microscopy, Positron Annihilation Spectroscopy, Glow Discharge Atomic Emission Spectrometer, and surface profilometry. INL has also supported advanced analytical methods for prediction of the behavior of solid-state materials at the operating conditions of SOECs, including atomistic modeling methods [3]. Under the HydroGen EMN initiative, INL would work together with industry, university, and National Laboratory partners in the characterization and optimization of SOEC material sets for improved performance and durability utilizing advanced technologies such as computational materials engineering, additive manufacturing, and advanced diagnostics. Materials research is needed for interconnects, interconnect coatings, contact layers, seals, electrodes, and electrolyte materials.