Average household income of seniors ages 65-69 is 29 percent lower than it was between the pre-retirement ages of 55 and 59, new research reveals. The Employee Benefits Research Institute discloses this finding in the September 2013 edition of "Notes," a monthly newsletter published by EBRI's Education and Research Fund. The research results are based on data from a University of Michigan "Health and Retirement Study," a national survey of older Americans.

The study tracked, in part, the income of 1,465 individuals who were ages 50-59 (inclusive) in 2000 and whose marital status was unchanged in 2010 when they were ages 65-69. Also surveyed were 3,358 individuals who were in an age range expanded by five years (ages 55-64 in 2000) and whose marital status was unchanged in 2010, when they were ages 65-74.

The report shows the average household income the surveyed individuals had in 2000 was $111,177, when they were ages 55-59. Average household income dropped to $78,437 in 2010 when they were ages 65-69. During the same period, the group's median household income fell to $54,839 from $88,002, a 38 percent decline.