How can someone currently at OSUT, under an active duty contract, transfer to NG or Reserves in order to go to school in the Fall 2018?

Sounds like he is contracted active duty and I really don't see him convincing his commander to grant a transfer to the reserves (via a form DD-368?), especially when he is a brand new private. It's kind of bad planning to apply for college and enlist active at the same time, unfortunately a contract is a contract. If the school has a online program then it might be salvageable. Also if he did manage to transfer, he would probably have to sign a new contract that would cancel the old contract out. Meaning any bonuses he received may have to be paid back. It's really a question for his unit, some S1 people on rally might you give you more information but they cannot predict what decision his unit will make. Plus his MOS makes a huge difference, Reserves are usually more support MOS and NG are more combat. For instance if he was 11B then he would have to go NG.

Personally, I would convince him to stay on point and finish his 3 years. He'll be 21 (?) when he gets out and have a much better sense of himself and what he wants to do with his life. The Army is not just about serving time, it's also about developing yourself, maybe not like a dream school way but it does teach you some hard lessons that are just as valuable.

Good Luck.

So basically he's wanting to renegotiate his contract, immediately after signing it? Good luck with that. I'm not aware of any process to shift to the Reserves or NG immediately after going onto AD.

There is a potential early out of his enlistment for school. I used it myself in order to get released early at the 3 year mark of a 4 year active duty contract. If his dream school is a college / university with Army ROTC, there is the Green-to-Gold option.

The program, which has highly competitive application process, allows Army enlisted personnel to receive an early honorable discharge to obtain an undergraduate or graduate degree. He would have to have two years of service at discharge time, be accepted at his dream school (again, must have college ROTC unit) and agree to return to the Army as a commissioned officer after graduation.

URL: https://www.goarmy.com/rotc/enlisted-soldiers.html