It might be worth taking a closer look at that “insured up to $100,000” sign that sits in the lobby of every bank.

With federal regulators seizing the failed California bank IndyMac (IMB) on Friday-- marking the third largest bank collapse in U.S. history--financial planners said now is the time to determine if your deposits are insured against a bank failure. 

“People are nervous,” said Eric Aanes, owner of Titus Wealth Management in California. “It’s nerve-racking not knowing who’s telling the truth.”

The collapse of IndyMac, which had $19.1 billion in deposits at the end of March, has raised concerns over what might happen if other banks fail and users' deposits go up in smoke. Regulators said the bank had approximately 10,000 customers with a combined $1 billion in uninsured deposits. Those deposits could potentially vanish as quickly as IndyMac did this weekend.

All bank deposits are insured by the Federal Deposit Insurance Corporation, commonly known as the FDIC, which guarantees each customer an insurance policy up to $100,000 for deposit accounts and up to $250,000 for retirement accounts.

But that statement is not as simple as it seems.

The $100,000 policy applies to a customer's combined accounts with a bank, the FDIC said on its Web site. If a customer has $50,000 in a savings account and $75,000 in a checking account at JPMorgan Chase, the FDIC insures only $100,000 of the total $125,000 in those two accounts.

However, if a customer keeps $75,000 in a checking account with JPMorgan Chase and then $50,000 in a savings account with Bank of America, the total of those combined deposits are fully insured by the FDIC because they are at separate financial institutions.

While the failure of a bank sounds scary, the process is actually rather simple for customers if they have less than $100,000 at a bank. When the FDIC took over IndyMac, regulators said bank customers were able to access their funds via ATM card. Checks drawn on IndyMac-based accounts are still accepted and processed as normal.

Federal regulators said the only features not available to IndyMac customers was online banking - which is a temporary problem they are working to resolve.

Financial planners said consumers should diversify their deposit accounts among multiple institutions, especially if they bank with regional banks like National City Corp. or even larger banks like Washington Mutual.

“Go with a large bank,” Aanes said. “Spread your deposits around and keep them below the $100,000 level. It will alleviate any concerns you have about what’s covered and what’s not covered.”

While many smaller and regional banks have offered CDs or money market accounts with attractive interest rates, it's best to avoid them, Aanes said.

"Those rates might be attractive, but they have significant risk attached to them," he said. "They might be offering these rates just to keep customers."

There is hope for customers with more than $100,000 in one bank, said Laura Bruce with Bankrate.com.

“You might have to wait until the FDIC liquidates all of the bank’s assets, but there’s a chance you may get a portion of those deposits back,” she said.

In the case of IndyMac, federal regulators said it plans to pay uninsured deposits a dividend equal to 50% of the uninsured amount. Any additional payments by the FDIC will depend on how an asset sale goes, regulators said.