We didn't have a good experience this year with grade skipping at our Montessori School.

DS has a late birthday. The cut-off date for kindergarten in our district is September 1, and his birthday is October 1. If he went to public school, he would have started kindergarten this past fall. Instead, he started first grade at our Montessori school Since the classwork is differentiated, he's doing 3rd grade math and 3rd grade reading.

We started Montessori school so that we could do this type of acceleration. DS has been reading since before his third birthday. We started him in a mixed age Montessori primary (mixed pre-K and K) classroom last year, because he was already well past the kindergarten curriculum and the first grade curriculum at our public school. The Montessori school agreed and this fall they moved him to the lower elementary classroom (1st-3rd grade). That's been great for his academic work and not that great socially. He's not very socially mature, and was the youngest kid in the class. He didn't fit well with the older kids in his class, and become somewhat disruptive. It's been a rough year, behavior wise. I wish that I had left him in the primary classroom and asked his primary teacher to do more differentiation with him. Montessori is all about differentiation, so it wouldn't have been that big of a deal.

YMMV