Who has the final authority to make the ATO determination?

The Authorization Official (AO) holds the final authority to make the ATO (Authorization to Operate) determination. This role is crucial within the risk management framework, as the AO is responsible for accepting the risk associated with operating an information system. The AO assesses the security posture of the system based on the information provided through security assessments, risk assessments, and other evaluations, ultimately deciding whether the system can operate under certain conditions or if it needs additional security measures to mitigate identified risks.

The AO's authority is based on a comprehensive understanding of the organization's security requirements and regulatory standards, and they must balance security needs with operational capabilities. This decision-making power underscores the importance of having a designated individual with appropriate authority and expertise to make informed judgments regarding system security.

While the Chief Security Officer (CSO), System Owner, and Unit Information System Security Manager (ISSM) play significant roles in the security framework and contribute to the assessment process, they do not possess the final say regarding the ATO determination. Their responsibilities typically involve overseeing security policies and practices, managing system functionalities, and implementing security controls, respectively. However, the ultimate responsibility rests with the AO, who must make the final decision on whether the risks are acceptable for operating the information system.