Code maintainability is crucial in .NET development because it impacts long-term project sustainability, scalability, and ease of updates. Clean, modular, and well-documented code allows new Dot Net Development to understand and enhance applications efficiently. Maintainability is ensured through coding standards, SOLID principles, and reusable components. Using unit tests, version control, and continuous integration further streamlines maintenance. Poorly written or overly complex code leads to technical debt, increased bugs, and delayed feature rollouts. Therefore, maintaining a consistent and clean codebase ensures lower maintenance costs, higher productivity, and improved application reliability over time.