Rejected students re-applying to different school

My son didn’t get admission to SCS in the ED round and is planning to re-apply to Dietrich in the RD. Has anyone started re-applying and worked on the Statement of Interest on the Regular Decision Consideration Form yet? Appreciate any tips on the re-apply

Is that even allowed?

i don’t think that’s allowed… for most schools at least if you’re rejected you’re rejected…

Find another university to apply to

yes. It’s absolutely allowed as long as you are applying to a different school than rejected in ED round. When contacted CMU admission office, they sent the following link for re-applying:

https://admission.enrollment.cmu.edu/pages/regular-decision-consideration-form

Read the sentence in bold in the above link