I disagree with Gail. Actually, there are SOME programs available, but you should talk to a local lender and see what those are. USDA has a loan program that offers basically zero money down, but it's restricted to certain rural areas. Some states have down payment assistance programs (basically in the form of a 2nd mortgage). If you don't go with those options, your minimum down payment for an FHA loan is 3.5%. And I also disagree with Gail's statement that you need a "substantial" amount of money for closing costs. Depending on your loan, closing costs could be anywhere from 1-3% of the purchase price....AND you can often negotiate that part into the contract to have the SELLER pay those.
HOWEVER, I do caution folks about trying to buy a house with zero money. If you can't afford a down payment or closing costs, what happens when your furnace breaks down this winter? Or a pipe freezes and your home is flooded? Or the water heater breaks? Or you get 13" of rain in 24 hours and your basement is flooded?
I have helped first time buyers get into a home with zero money down, and now...they struggle whenever something happens. Fence blows over in a big wind storm. OR...house was flooded in the recent "great Colorado Flood of 2013" Their home was not in a flood plain, and therefore didn't have flood insurance. Luckily they still HAVE a home, but their finished basement is ruined and they have no money to fix it.
I would encourage you to buy a home when you have money to put into it.... more