Account balances in 401(k) and IRA/Keough plans sank at least 15% from year-end 2007 through mid-June 2009, according to recent data from the Employee Benefit Research Institute (EBRI).

EBRI compiled statistics from the 2007 Survey of Consumer Finances, the Federal Reserve Board's triennial wealth survey, and adjusted them to account for the recent market meltdown as of June 19.

The median balance in 401(k) plans was $26,578 by mid-June, a 16.4% drop from $31,800 at year-end 2007. That number, in turn, was up 16% from the Fed's 2004 wealth survey. The biggest drop came from families with more than $100,000 in income (-22%) or whose net worth is in the top 10% (-28%).

Regarding IRA/Keough plans, the median value was 28,955 by mid-June, down 15% from $34,000 in 2007. In turn, that was a 3% rise from 2004.