The typical American worker stays at a job for only four years. As many find out, switching employers can wreak havoc on your retirement plan.

The U.S. Government Accountability Office estimates two in five employees cash out small 401(k) balances when they leave their jobs. In the process, they pay taxes and penalties while never giving their money a chance to grow. Or, workers can end up accumulating a collection of 401(k) plans throughout their careers, with small balances spread out at various old employers. It’s a huge hassle to roll those old 401(k)s into a current 401(k) or into an individual retirement account, and it’s easy to lose track of what you’ve saved, and where.

Senator Elizabeth Warren, the voluble Democrat from Massachusetts, thinks we need a “Retirement Savings Lost and Found.” Along with Montana Republican Senator Steve Daines, Warren on Tuesday introduced a bill that would create a database of your old retirement accounts. The bill would also allow abandoned retirement accounts to be invested in target-date mutual funds, an increasingly popular option that invests in a mix of stocks and bonds based on a participant’s age and retirement date. Right now, many stranded 401(k) accounts end up in cash, where their value is steadily eroded by inflation.