Our Gracie is 12 weeks old and I am preparing for the right time to switch as well.
We were told to switch to adult about 6 months OR as soon as she is spayed (which is also at 6 months). The logic on the spaying note is that they are likely to put on weight after the procedure and no longer need the extras that puppy food provides.
We feed Earthborn Holistic Puppy Vantage presently but many people feel their young ones the adult grain free formulas. IMHO as long as you are feeding a natural really healthy food that is giving full vitamins and nutrients you are probably OK.
