Yes, I am using Microsoft Graph API, sorry I forgot to mention that in my original post. I actually came across that same thread during my research before posting this question, but I thought it was a little different since It's talking about using delta queries, which are meant to return the changes to a resource since you last accessed it, whereas I am talking about initially loading the state of the the resource for the first time. After considering it a little more carefully though, I suppose if Microsoft isn't going to return the deleted event during a delta query, it likely won't ever return a deleted event. I guess I'll have to just compare occurrences and hope it doesn't hurt my performance too bad. Thanks for your help.