The agency said previously reported July increase was revised lower from 1 percent to 0.8 percent.
The index keeps track of prices of homes with mortgages backed by either the Federal National Mortgage Association or the Federal Home Loan Mortgage Corp., better known as Freddie Mac and Fannie Mae, respectively.
The FHFA said the price index, while up for 19 months, is 9.4 percent less than the April 2007 peak. Prices are currently near April 2005 levels.
Among the nine U.S. census regions, the home price index ranged from a 0.5 percent decline in the South Atlantic division to a 1.3 percent gain in the Mountain division.
On a 12-month basis, price changes have ranged from a 4 percent gain in the Middle Atlantic division to an 18.2 percent gain in the Pacific division, the agency said.