Interim Authority to Test (IATT)

An Interim Authority to Test (IATT) is a temporary, limited authorization that allows a system to operate in a controlled environment for testing purposes before it has received a full ATO. It permits evaluation of the system's functionality and security in a real or near-real environment while final security controls are still being implemented or assessed.

IATTs have strict conditions — they specify what testing is allowed, for how long, and under what constraints. They're commonly used during system development when you need to connect to live networks for integration testing but haven't completed the full RMF process yet.