Where do I get an NPI assignment letter?

Hi all, I am applying to get my medicaid provider number, I have all the paperwork all filled out, ready to mail. On my required documentation checklist it says "submit a copy of your National Provider Identifier assignment letter issued by CMS". Do I have to have that to be able to apply for my medicaid number? If so, how do I get one? I have been looking all over on the internet, sooo confusing.

Also, anyone know of any website that lists available jobs for RN's with medicaid numbers? I live in upstate New York....helpppppp....any help would be greatly greatly appreciated!!!!!