In PA they review the case every year, if you cant provide health care they can cover a child til 18. Parents either go without or get in through their job and since PA is one of those states that mostly employ for up to 36 hours theres ALOT of uninsured adults
I live in Illinois, I have been getting it since I was pregnant and I still get it along with DD whose was born in May of 2010. More specifically I know based on your income and family size determines 1. if person is eligible 2. Whether you pay nothing or a monthly premium and/or copays. However there should be a website for your state's insurance that would give you more specifics to their program.
In ky I will lose mine three months after birth. But the lady I talked to at the office said my little one will keep hers. If for some reason I make too much for her to qyalify (I highly doubt will ever happen) then her dad will be required to cover her