This guidance is for program and agency staff who have identified the need to develop a new data system or make major enhancements to an existing system. Key considerations are presented as questions to help guide staff through the initiation and planning process. The system initiation phase requires a broad team with the expertise and knowledge to gather information, plan, and explore various options based on these considerations. The key considerations are designed for group discussion and group planning. The phases of developing a new data system or enhancing an existing one are commonly referred to as a system development life cycle (SDLC). While there are minor variations across different SDLC models, almost all begin with initiation. The initiation phase covered in this brief requires creating a team, gathering information planning to propose a high-level solution, and developing a path to that solution. This initiation work supports the SLDC phases that will come later: requirement analysis, design, development, acceptance testing, and finally deployment. [This brief is an updated rework of the 2015, "Key Considerations for Initiating and Planning a New Data System or Major Data System Enhancement" by Laura Hudson, Nancy Copa, Jamie Kilpatrick, Robin Nelson, and Bruce Bull.]