Grade O-3, bypassing Ensign (O-1) and Lt. Junior Grade (O-2) in the process. Usually reserved for medical and legal officers, for pay purposes.
Gotta be for more than just pay. Such positions are, one would think, positions of Authority. They do have to be able to give orders. Rank reinforces that in a military structure.
that’s all after rotc and or basic, not just one day civi, next enlisted officer, as is case here i think