Income Rises With Age: 80 Percent Of Millionaires Are Over 45 Years Old: Only 3 Percent Are Under 35 Years Old

From Tax Foundation, "Millionaire Taxpayers Tend to be Older" by Scott A Hodge:

For most Americans, incomes tend to rise with age. Thus, it is not surprising that in 2011, more than 80 percent of millionaires were older than age 45, and close to half of all millionaires (48 percent) were older than age 55. In fact, there are still more millionaires over the age of 65 than between the ages of 35 and 45. Moreover, despite the publicity given to the growing number of young millionaire athletes, celebrities, and entrepreneurs, only about 3 percent of all million-dollar tax returns are filed by taxpayers under the age of 35.

Source: Tax Foundation