In this article, I describe how gender bias can affect the design, testing, clinical trials, regulatory approval, and clinical use of implantable devices. I argue that bad outcomes experienced by women patients are a cumulative consequence of small biases and inattention at various points of the design, testing, and regulatory process. However, specific instances of inattention and bias can be difficult to identify, and risks are difficult to predict. This means that even if systematic gender bias in implant design is an ethical issue, it is one with no clearly blameworthy player. From a practical perspective, there is no single obvious point at which to intervene. Philosophers working in other areas have explored structurally similar moral problems—sometimes referred to as “moral aggregation problems”—such as the type of environmental harm caused by small actions of many players. I describe key features of these type of problems and strategies to address them. I then draw on these to suggest an approach to gender bias in medical implant design and use.