NEW YORK — The money we keep in the bank is supposed to help us sleep at night, not cause nightmares.

IndyMac Bank's collapse a few weeks ago, and the fury that followed when some account holders couldn't get their money out, should serve as a reminder to get smart about the rules of banking, though.

Depositing money into a bank isn't equivalent to putting it under your mattress. If the money isn't insured, you can't just pull the cash out should the bank fail. There are federally set insurance limits of $100,000 per depositor per bank and $250,000 on retirement accounts.

Beyond that, there's no guarantee you'll get all your cash back unless the bank's assets sell.

Let's be clear: There's no sign that many banks will fail in the coming months. There are nearly 8,500 banks and savings and loan institutions in this country, and so far this year, eight have gone under, the largest being IndyMac. That's up from three failures last year and none in 2006, according to the Federal Deposit Insurance Corp., or FDIC, which backs deposits at the nation's banks.

But that doesn't mean more aren't struggling with the continuing pressures of tighter credit, tumbling home prices and rising foreclosures — which together are draining capital levels. Before any more collapse, it's best to know how to best protect yourself.

Part of the problem is that a bank could fail with little warning. That happened at IndyMac. While it was experiencing losses on earnings and its capital position was waning, it wasn't even on the FDIC's unpublished "watch list" when it was taken over by the FDIC. Ninety U.S. banks were on that list in the first quarter; banking experts say hundreds more are potentially at risk.

In late June, Sen. Charles Schumer, D-N.Y., raised concerns about IndyMac's financial health. Company officials responded by saying they were working with regulators to shore up its "safety and soundness." That still didn't stop some depositors from pulling more than $1 billion worth of money out.

By July 11, things had turned so bad at the Pasadena, Calif.-based bank that its assets were seized by federal regulators. By assets, it was the largest regulated thrift to fail ever.

Photos of depositors lined up to get their money out of the failed bank blanketed newspaper covers and led evening newscasts. The chaos was quickly compared to Depression-era bank runs.

For 10,000 of its 275,000 customers, the news was particularly bad because they had more than $100,000 in the bank, adding up to uninsured deposits valued at $1 billion.

They were told they would receive just 50 cents on their dollar for their money and that they had to wait for the rest.

Now getting their money back hinges on the government's ability to sell the bank's troubled assets to another financial institution. If it happens quickly, they don't have a problem.

That's how it is playing out with Bradenton, Fla.-based First Priority Bank, which was taken over by the FDIC on Friday and then sold to SunTrust Banks Inc.

The FDIC said it expected this week to pay the 840 First Priority accounts holding $13 million in uninsured deposits the remaining 50 percent of their uninsured balance.

That's a best-case scenario. No one should count on it happening next time. Typically, uninsured customers at failed banks get back 70 cents to 80 cents for each $1 they have deposited, according to FDIC spokesman Andrew Gray.

That's why it is up to bank customers to know if their deposits are above the insurance limits and take steps to prevent that from happening. This is particularly crucial for small businesses, which often keep large deposits at banks since they need money available to fund their operations.

If your deposits exceed the insurance limits, spread your money around to a few different banks — not different branches of the same bank but different banking institutions. Also, open accounts in the name of different family members, and make sure you ask your bank if your deposits are insured.

Another option is the use of the FDIC's Certificate of Deposit Account Registry Service, or CDARS, which splits deposits into chunks under the $100,000 insurance limit and funnels the money out to 2,000 banks in the network. Only banks considered "well capitalized" by the FDIC are included.

Depositors also should know as much as they can about the banks holding their money. Are they reporting big losses? How is their capital position? How do their finances compare with their peers?

This isn't the time to gamble with your money.