Molten carbonate fuel cell technology (MCFC) is now entering the commercialization stage. M-C Power Corporation (MCP) was established in 1988 with the sole purpose of bringing the internally manifolded (IMHEX®) molten carbonate fuel cell concept to full commercial viability. Research and development is being carried out by the Institute of Gas Technology (IGT) and full-scale cell and stack manufacturing and testing are being performed at MCP.MCP has scaled IGT molten carbonate fuel cell technology from the 1 ft2 level to commercial scale of 1 m2. The scale-up involves active area components, separator plates, stack fixturing, and operating conditions and procedures. MCP has established prototype commercial facilities for manufacture of active area components. The facilities have been used to manufacture active components for a 20 kW commercial-area IMHEX® stack currently being operated in MCP's stack testing facility as well as components for several 1 ft2 stacks. This paper discusses MCP's stack testing program.