ABLE accounts were authorized by federal law by adding §529A to the Internal Revenue Code in December of 2014. They are actually allowed to be operative by 1-1-15.
However, they are not yet in effect in NY (probably effective around 2-15) and you can't set one up.
New York passed the legislation (S 4472), however as of 8-14-15, the Governor has not yet signed it into law. NY's law is effective 180 after it is signed into law.
So, if you live in NY, regardless of whether it is Pound Ridge or South Salem until the law is effective, your only option is a special needs trust which is more complex and expensive.