What classification level is associated with "exceptionally grave damage" to national security?

The classification level associated with "exceptionally grave damage" to national security is Top Secret. This classification is the highest level of classification in the U.S. government system and is used to protect information that, if disclosed, could cause significant damage to national security. The definition emphasizes the severity of potential harm, which is reserved for only the most sensitive information.

Top Secret information requires stringent access controls and clearance processes, ensuring that only individuals with the necessary authorization can access such data. Other classification levels, such as Confidential and Secret, denote varying degrees of potential damage but do not encompass the same level of severity as Top Secret. Restricted is not typically recognized as a formal classification in terms of national security damage assessments and thus does not fit within this context.