If you were to get rejected by a college as an early decision applicant, will you still be able to apply as a regular decision to the same school?
No. You must choose early or regular, you can’t do both.
Depends upon the school but in most cases no. Look up the school’s ED policy.
This is from Ask the Dean::::::::::::::::::
Question: If I apply to a college through Early Decision or Early Action, but I am not accepted, can I apply again through Regular Decision?
If you are denied outright (“rejected”) in the Early Decision or Early Action round, then you CANNOT reapply. In most cases, if a college thinks that you are at least a borderline candidate but they aren’t willing to commit to you during the Early Action or Early Decision process, they will “defer” you and then reevaluate your credentials with the Regular Decision pool. (I said, “In most cases” because there are a handful of colleges, such as New York University, that do not ever defer Early applicants … they only admit or deny them.)
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If you are rejected ED you cannot reapply to the same school that year. You get one shot at it.