The new protections represent an effort to avoid a repeat of the crisis and subsequent recession in which almost 9 million workers lost their jobs and the U.S. government committed $245 billion to save the financial system from collapse.

Like MF Global

The goal of policy makers is to ensure that if one of the largest financial institutions fails in the next crisis, shareholders and creditors will pay the tab, not taxpayers.

"Two or three years from now, Goldman Sachs should be like MF Global," said Dennis Kelleher, president of the nonprofit group Better Markets, who doubts the government would allow a company such as Goldman to repeat MF Global Holdings Ltd.'s Oct. 31 collapse.

Dodd-Frank, the most comprehensive rewriting of financial regulation since the 1930s, subjected the largest banks to higher capital requirements and closer scrutiny. The law also barred federal officials from providing specific types of assistance that were used to prevent such firms from failing in 2008. Instead, the Fed will work with the FDIC to put major banks and other large institutions through the equivalent of bankruptcy.

"If a large financial institution should ever fail, this reform gives us the ability to wind it down without endangering the broader economy," Obama said before signing the act on July 21, 2010. "And there will be new rules to make clear that no firm is somehow protected because it is too big to fail."

'Completely Unrealistic'

Officials at the Treasury Department, the Fed and other agencies have spent the past two years drafting detailed regulations to make that vision a reality.

Yet the big banks stayed big or, in some cases, grew larger. JPMorgan, which held $2 trillion in total assets when Dodd-Frank was signed, reached $2.3 trillion by the end of 2011, according to Federal Reserve data.

For Lacker, the banks' living wills are the key to placing the financial system on sounder footing. Done right, they may require institutions to restructure to make their orderly resolution during a crisis easier to accomplish, he said.

Neil Barofsky, Treasury's former special inspector general for the Troubled Asset Relief Program, calls the idea of winding down institutions with more than $2 trillion in assets "completely unrealistic."

'No Progress'