; (J) benefits promised with respect to the program or project at initiation; (K) benefits delivered with respect to the program or project as of the date of the report; (L) whether the program or project was cancelled and, if so, a description of why and when; (M) for cancelled programs or projects, whether there were any costs associated with the decision to cancel and, if so, a description of the amount of the costs (including for both the Administration and the private sector); (N) the metrics, milestones, and deadlines set for the program or project and how the Administration tracked and ensured compliance with those metrics, milestones, and deadlines; (O) how the Administration conducted oversight of the program or project and any related stakeholder collaboration efforts; (P) the status of the program or project as of the date of the report; and (Q) an assessment of the key risks to the full implementation of the program and a description of how the Administration is mitigating, or plans to mitigate, those risks; (9) the date upon which, or milestone by which, the Administration anticipates NextGen will be complete; and (10) any lessons learned during the NextGen effort, and whether, how, and to what effect those lessons have been applied. (b) Inspector general report Not later than 270 days after the date on which the report required under subsection (a) is submitted, the inspector general of the Department of Transportation shall review the report and submit to the appropriate committees of Congress a statement of the inspector general that— (1) determines the accuracy of the information reported; (2) describes any concerns with the accuracy of the information reported; (3) summarizes concerns raised by the inspector general, the Government Accountability Office, and other sources with respect to the Administration’s implementation and oversight of NextGen since the date on which NextGen began