Biogas can be directly utilized in Solid Oxide Fuel Cells (SOFCs), as it can be reformed to H2-rich mixture in the anode of SOFCs. However, the rate of reforming reaction significantly changes along the flow field due to the rapid conversion of CH4 in the inlet region. Since the reforming reactions are endothermic, a dramatic temperature gradient develops along the flow field, resulting in thermal stresses on the adjacent SOFC components. Taking the reforming reactions out of SOFC domain by indirect internal reforming reduces the thermal stresses to an extent, which can be further mitigated by designing a graded catalytic domain for an even temperature distribution. In this study, we demonstrate a reliable and durable operation of SOFC equipped with an indirect internal reformer graded in terms of catalyst loading.