A new study shows that the number of unbanked households in America - those with no bank accounts - has increased since 2009.

Ten million households, or one in 12, are unbanked, said the Federal Deposit Insurance Corporation (FDIC) in its National Survey of Unbanked and Underbanked Households, using 2011 data, the second survey of its kind.

The number of unbanked households increased since the FDIC's first survey in 2009, growing 0.6 percentage points to 821,000.

Meanwhile, 20.1 percent of U.S. households are underbanked, meaning they have a checking and/or savings account but have used non-bank money orders, non-bank check cashing services, remittances, payday loans, pawn shops and other non-traditional banking means.

"It's significant and positive that a respected public agency continues to track and study the issue of financial inclusion and, in this case, to note that the problem has, if anything, grown worse since its landmark 2009 study," said Timothy Flacke, executive director of the nonprofit Doorways to Dreams (D2D) Fund, which makes financial products for low- and moderate-income consumers.

Flacke said the FDIC study highlights a basic fact, that "those who are disconnected from the financial system are at a significant disadvantage in trying to save and build financial security."

The report says almost a third of U.S. households, 29.3 percent, do not have a savings account.

Flacke said that is one reason why his non-profit organization, based in Allston, Mass., supports the U.S. Savings Bond program, especially for those who are not connected or fully connected to the private financial system.

He said the FDIC study also highlights the need for innovation to make sure more people are included in the financial system.

That is reflected in the Treasury Department's recent decision to run a public challenge, called MyMoneyAppUp, in partnership with D2D Fund and the Center for Financial Services Information, to encourage new mobile technologies to increase financial access.

The challenge asked the public to submit ideas to help Americans "shape their financial futures" for cash prizes up to $10,000. Winners of the challenge will be announced Sept. 28.

"The lack of progress in increasing financial system participation between the 2009 and 2011 FDIC studies suggests new approaches are needed to increase financial inclusion," Flacke said.