Twenty-one percent of those interviewed, between the ages of 60 and 75, say they don't know when they will be able to retire, and nearly one in five or 19 percent, with assets between $100,000 and $250,000 feel they will need to work until at least age 80, a sentiment reported by 25 percent of middle class Americans. Twelve percent of affluent Americans said they will work until age 80.

"We find the rich versus poor narrative in the U.S. is more complex than we might expect, with fears and concerns about retirement felt along the income spectrum," said Karen Wimbish, director of retail retirement at Wells Fargo. "Even among those considered 'well off,' many seem to fear a sharp drop in their post-retirement standard of living due to insufficient retirement savings."

Affluent women surveyed are significantly less confident about retirement than men. The least confident of all are single women, and the most confident are married men.

"Despite the fact that women hold half the high-paying managerial positions in the U.S. work force and they make a majority of household buying decisions, women continue to lag behind men in their confidence in preparing for retirement, and this is particularly true for single women," Wimbish said.

The affluent men surveyed have saved a median of $400,000 for retirement versus $250,000 saved by affluent women. Affluent men also say they need more: a median of $750,000 to support themselves in retirement, compared to $500,000 estimated by affluent women.

While affluent Americans are slightly more willing than middle-class Americans to take a reduction in these benefits to help the country (47 percent of affluent versus 43 percent of middle-class), among the affluent there is no sharp drop-off among people closer to retirement. Among the middle class, willingness to take cuts plunged from 47 percent for people in their 40s to 28 percent for people in their 50s to 19 percent for people 60 to 75. Among the affluent, the willingness to take cuts was relatively flat at 49 percent for people in their 40s, 43 percent for people in their 50s and 44 percent for people age 60 to 75.

Affluent Republicans (52 percent) are somewhat more willing than affluent Democrats (46 percent) to take personal cuts. Other affluent Americans who are more open to benefit cuts include those who have a child under the age of 18 (54 percent), have investable assets of $250,000 or more (52 percent), feel confident the stock market is a good place for retirement investments (52 percent), and are married (50 percent).

Among the affluent surveyed, 401(k)s or similar plans represent 42 percent of household assets. Affluent Americans contribute a median of 10 percent of their incomes to 401(k) accounts, compared to 6 percent contributions by middle class Americans.

"The importance of the employer-sponsored plan in helping save for retirement can't be stressed enough," Wimbish said. "Many people simply would not have saved as much if it wasn't for the 401(k)."

Wells Fargo & Company is a nationwide, diversified, community-based financial services company with $1.3 trillion in assets. Harris Interactive is a custom market research firm, leveraging research, technology, and business acumen to transform relevant insight into actionable foresight.