What is an Authority to Operate (ATO)?

An Authority to Operate (ATO) is an official declaration that an information system is cleared for use after it has undergone a thorough security assessment and evaluation. This determination results from a comprehensive review process to ensure that the system meets all necessary security requirements and compliance standards. An ATO signifies that the organization deems the risks associated with operating the system have been adequately mitigated and that it is authorized to be deployed within the operational environment.

This declaration is crucial in maintaining the integrity and security of information systems, especially within government and defense-related contexts, where data protection and risk management are paramount. The ATO not only confirms that control measures are in place, but also indicates ongoing monitoring and assessment are necessary to maintain the authorization over time.

The other options do not provide the same significance or context as the ATO. Guidelines for software installation refer to best practices for deploying software, an inventory of security tools lists security resources without indicating authorization, and a formal request for system upgrades is related to improving system capabilities rather than authorizing the use of the system itself.