How are user accounts in IDACS typically managed?

User accounts in IDACS are typically managed by agency administrators who are responsible for assigning and overseeing access levels. This structure ensures that access is tailored to the specific needs and responsibilities of users within their respective agencies. Agency administrators have the necessary knowledge of their personnel and workflows, which allows them to effectively determine who should have access to certain data and functionalities within the system. This layered management helps maintain security and compliance with regulations, ensuring that sensitive data is only accessible to authorized personnel.

The other choices do not reflect how user accounts in IDACS are actually managed. For instance, external contractors managing accounts would introduce potential security risks, as they may not have the comprehensive knowledge of agency-specific needs. A centralized national database for all users does not exist within IDACS, as the system's architecture is designed to function within the framework of individual agencies. Lastly, user self-management without oversight would compromise security protocols, as it would lack the necessary checks and balances to ensure sensitive information remains protected.