Well as a recruiter, i dealt with a lot of prior service that wanted to return to duty. If the medical condition is better you can request to get a waiver to come back in as you might notice on your DD 214 the RE CODE is either 3 or 4. It shouldnt be a 1 due to the fact you did a medical discharge. You were medically temporarily retired so i would assume you got a DD 214. But that is what you will do. I could be wrong but I think you have to go back through recruiter and MEPS and must be medically approved again.