<p>So I want to send in a letter of rec from my research mentor. My question is, if my research mentor sends in his letter of rec before I submit my application, would it go in my file and be reviewed with the rest of the app (when the app is turned in) or since they wouldn't have an app for it to go with, would it kind of be ignored?</p>
<p>I think they would wait until your whole application comes through. They definitely won’t ignore it.</p>
<p>Different elements of your application can arrive separately. Your transcripts too will be sent apart. They will put everything together before reviewing. You have nothing to worry about. Do give your research mentor your Common App ID though which should be included in his/her letter. Good luck.</p>
<p>^^agree. You should be fine. Good luck.</p>