When doing the ROTC SMP program, do you have to commission into the same branch that you are drilling with?

Up to you and the unit CO...I requested an LOA from my BN CDR during my Senior year & got it. Some considerations...were you prior enlisted in that unit? - does it have a command climate you want to be in - there may be other means they have of recruiting officers - talk to Company Staff, S1, Commander & see if they are willing to accept you.

Cadet CPL Broc Peterson So you can choose if you want it to be then yes, but it doesn't have to be, if you don't select a unit/position the reserve/guard will choose for you. My advice is to find the unit you want to commission into and transfer to that unit, during your MS3 year you can get a paragraph and line item number from that unit and you will be guaranteed to be commissioned into that slot with the appropriate branch. If you don't select a unit you'll be put into the state/reserve selection process and they will assign you a branch and a unit based on their needs and your selected preference.

Not typically, during your MS1 and 2 years they will put you wherever there’s a spot really. Your 3 and 4 years you can typically chose based on what branches you’re interested in, and they may even put you in the Unit/PLT that you will be leading upon commissioning. But your state/unit could do something completely different, just my experience!