Is this preK program like the one here in CA they started a few years back and only available to some 4 year olds? California changed it's kindergarten cutoff to be more in line with the rest of the country. For years it was Dec 2nd, but after 3 year transition next year it will be Sept 1. The CA preK (Transitional K) program is only offered to 4 year olds who turn 5 between Sep 1 & Dec 2nd. http://www.cde.ca.gov/ci/gs/em/kinderfaq.asp#E2

I know New York is/was? a state that with a similar Dec/Jan K cutoff. This article doesn't really describe the program.

In California this new preK wouldn't really change much. K is not required, and thus preK program is not required. By state law you HAVE to go to school by 1st grade. (Or show you are homeschooled.) The new preK program does not affect the age cutoffs for 1st grade. The only way around the cutoff's taht I know of is to put a child in private school till 2nd grade and then transfer OR start them at their "age" and convince the school to skip.