Can someone explain NACA to me? I am looking to buy a house and it seems to good to be true.

My wife and I are looking to buy a house in about a year and I just heard about a program called NACA. It seems to offer 3.5% financing with no down payment, no closing costs, and no fees. I also read somewhere that you can buy down your interest rate. This seems to good to be true and I wanted to know if anyone knew any more about it. I have been doing research but a lot of it seems to point towards attending one of their workshops.

For some added info, my wife and I have excellent credit, and good jobs, and will be looking for a home in the 350 - 450 K price range. We'll have about 20% of a down payment at this point next year if we went with a traditional mortgage.

Any info would be appreciated! Thanks!