Just to clarify, officers don't enlist but are instead granted a commission.
Just to re-clarify my brother enlisted with his package for OTS already put together with endorsements from two Senators, one being Sam Nunn. He went through USAF Basic and when he and his wife got to Barksdale Air Force Base he sewed on Staff Sergeant and a had a slot for OTS at Medina Annex.
Exactly. He enlisted as a staff sergeant and was granted a commission after he completed OTS.