A large number of mass affluent Americans are unsure about their financial future, with 63% reporting it will be harder to save for the long term five years from now and 45% saying they are more conservative than they were a year ago, according to the 2011 Merrill Edge Report.

The report from Merrill Edge, an affiliate of Bank of America-owned Merrill Lynch, is an in-depth look at the financial concerns and priorities of consumers with $50,000 to $250,000 in investable assets. According to Merrill Edge, the mass affluent represent the fastest growing segment of American investors, with more than 32 million people between the ages of 35 and 55 falling into this category.

Dean Athanasia, mass affluent and small business segment executive for Bank of America, said the mass affluent represents an underserved segment of the market that saves and plans very differently from the affluent.

According to the report, approximately 36% of respondents identify themselves as having a low tolerance for risk, 41% expect to retire later than originally planned, and 85% expect their retirements will be different from what their parents experienced.

The report also showed that 51% of this segment did not have a formal or written financial plan.

"For this client base, which has been accumulating assets and is coming into a different phase in their lives, I think that is surprising," Athanasia said. "That's something a financial advisor should be discussing with their clients every time they meet with them."

Among the respondents' top financial priorities were tracking and managing money (72%), saving for retirement (67%) and balancing short- and long-term financial needs (63%). Among their top concerns were rising healthcare costs (76%), ensuring that retirement assets would last throughout their lifetime (67%), and being able to meet their lifestyle expectations for retirement (58%).

Moreover, 58% of respondents said they would be more confident in their ability to meet financial goals if they had access to a complete picture of their finances and investments.