Will I be able to submit both old and new (March 2016 and later) SAT scores to colleges? Or will I have to choose between the two? I'm graduating high school in 2017.
Yes, it looks like most colleges will be accepting both old and new SAT scores from the Class of 2017. Though you should still double check with any college you're applying to before you send in your scores, all of the 30+ colleges we asked said that both would be accepted. In fact, some colleges may even require you to send all your SAT scores.