Applications ranging from MRI and CT scanners to the latest radiation and radiotherapy equipment—sometimes collectively referred to as the “big iron” of the medical world—have a variety of demanding requirements when it comes to powering key elements of the equipment. Here, power delivery can range from a few watts to more than 20 kW. What’s more, power ratings continue to rise as the systems become more complex, integrating more powerful electronics to support advances in 3D and 4D imaging modalities and improve diagnostic outcomes. In addition to addressing the ratings and safety requirements of these medical systems, designers are looking for efficient, high-power-density solutions that keep size to a minimum and heat dissipation low, offer good EMC performance, reduce ongoing energy costs, and simplify cooling overheads. Because these systems are expected to operate continually over many years, reliability and ease of maintenance are also important considerations. In this article, we look at the power supply design and operational requirements of big iron medical systems and how configurable, medically certified power supplies can be used to meet these requirements while simplifying system design.