For some people, the U.S. savings bonds they've bought end up forgotten in a drawer, closet or safe-deposit box.
But these days, when cash is king, those bonds may yield a nice surprise.
Your bond may have matured and stopped earning interest -- and that means it's time to cash it in.
"In these lean times, these savings bonds, which can be worth at least three to four times their face value, can be a great help to cash flow needs," said Joyce Harris, spokeswoman for the U.S. Bureau of the Public Debt, which conducts the government's borrowing operations.
Currently, there's $16.6 billion in unredeemed matured savings bonds, meaning they're no longer earning interest.
The value of matured unredeemed savings bonds is growing steadily each month, said Jack Quinn, chief executive of SavingsBonds.com.
"That means there are a lot of savings bonds out there that are still in drawers, not seeing the light of day," he said.
But Quinn said: "The redemption of savings bonds has been more pronounced these past nine months than it had been in a while."
Typically, outstanding savings bonds are "somewhere in the neighborhood of $200 billion," but as of the end of June, it's dropped to $193.5 billion, he said.
"When you see it down to $193 billion, that's a pretty big departure than what it used to be," Quinn said.
Savings bonds are mostly bought through employers' payroll deduction plans and stop earning interest after 30 or 40 years, depending on when they're purchased.
You have to keep an eye on this because the government won't notify you that you have a savings bond about to mature.
Generally speaking, you can cash in your Series EE bond a year after the date of purchase, but if you redeem it before it's 5 years old, you will lose three months of accrued interest.
However, you may be able to redeem bonds sooner if you live in an area that's been affected by a disaster, such as a flood, fire, hurricane, or tornado.
If you think you have a matured savings bond, go to www.treasuryhunt.gov, which tells you about savings bonds no longer earning interest.
If the bonds were bought in 1974 or later, you can just in put your Social Security number. The database can match the numbers against matured unredeemed savings bonds.
You can also find the current redemption value of your savings bond at the government's TreasuryDirect Web site.
However, before you redeem your saving bonds, you should be aware of the income tax implications.
The interest earned on your savings bonds is subject to federal income tax but can be deferred until redemption or maturity, whichever occurs first.
If you haven't reported the increased value of the bonds as interest each year, you must report all of the interest in the year you cash them in.
Savings bonds also are subject to estate, inheritance, gift, or other excise taxes, whether federal or state.
Because of the tax issues involved, there's a strategy to redeeming savings bonds.
Savings bond interest is compounded, so as your bond gets older, the interest continues to grow and becomes a really major part of the bond's value.
But don't let tax concerns prevent you from redeeming your bond if it's matured.
If you don't cash it in, you'd be giving an interest-free loan to the government, and who wants to do that?