Individuals who are employed as teachers for grades Pre-K through 12, law enforcement officers, firefighters and EMTs are offered incentives by HUD to purchase homes in a designated revitalization area.
The incentive is 50% from the list price of the home, however HUD does require that you sign a second mortgage and note for the discounted amount. HUD calls this the "Good Neighbor Next Door" program.
To qualify you must commit to living in the home for at least 36 month as your sole residence and meet the other requirements. For more information visit HUD's Good Neighbor Next Door Q&A Page.
HUD's GNND Q&A Page: http://www.hud.gov/offices/hsg/sfh/reo/goodn/gnndfaq.cfm