If I didn’t submit all of the previous cohort files from my institution, how can I conduct a Year-Over-Year study in ACES?

Only earlier submissions made by you will be listed. If someone other than you in your institution or educational system submitted earlier studies, either they can make the Year-Over-Year Study request in the ACES system or they can contact ACES via email and ask to request that the studies they submitted be made accessible to you.