Though I'm not sure you would actually WANT it before then. It depends on if you are talking about meta or phallo. With meta, you are depending on a certain amt of growth from T, so generally they won't do it til you have been on T for two years. With phallo, there are grafting techniques and so on where they take muscle and nerves from an arm (say) ,that is pretty heavy duty surgery for a very young person. And though young people are maybe physically more ready, there are psychological factors, as well. I don't know of too many very young people could handle this, being less patient generally and that sort of thing. (Yes, I know this is a generalization, but medical people generally have to go by these).
--Jay
