The FHA makes Countrywide Financial look prudent.

The Treasury has announced new “capital cushion” requirements for financial institutions to reduce excessive risk and prevent taxpayer bailouts. Seems sensible enough. Perhaps the Administration will even impose those safety and soundness standards on federal agencies.

One place to start is the Federal Housing Administration, the nation’s insurer of nearly $750 billion in outstanding mortgages. The agency acknowledged this month that a new but still undisclosed HUD audit has found that FHA’s cash reserve fund is rapidly depleting and may drop below its Congressionally mandated 2% of insurance liabilities by the end of the year.

At a 50 to 1 leverage ratio, the FHA will soon have a smaller capital cushion than did investment bank Bear Stearns on the eve of its crash. (See nearby table.) Its loan delinquency rate (more than 30 days late in payments) is now above 14%, or from two to three times higher than on conventional mortgages. Its cash reserve ratio has fallen by more than two-thirds in three years.

The reason for this financial deterioration is that FHA is underwriting record numbers of high-risk mortgages. Between 2006 and the end of next year, FHA’s insurance portfolio will have expanded to $1 trillion from $410 billion. Today nearly one in four new mortgages carries an FHA guarantee, up from one in 50 in 2006. Through FHA, the Veterans Administration, Fannie Mae and Freddie Mac, taxpayers now guarantee repayment on more than 80% of all U.S. mortgages. Sources familiar with a new draft HUD report on FHA’s worsening balance sheet tell us that the default rates have risen most rapidly on the most recent loans, i.e., those initiated or refinanced in 2008 and 2009.

All of this means the FHA is making a trillion-dollar housing gamble with taxpayer money as the table stakes. If housing values recover (fingers crossed), default rates will fall and the agency could even make money on its aggressive underwriting. But if housing prices continue their slide in states like Arizona, California, Florida and Nevada—where many FHA borrowers already have negative equity in their homes—taxpayers could face losses of $100 billion or more.

So far Congress has pretended that these liabilities don’t exist because they are technically “off budget.” They stay invisible until they move on-budget when a Fannie Mae-type cash bailout is needed. The Obama Administration is at least finally catching on to these perils and last week proposed some modest reforms. These include appointing a “chief risk officer” at FHA, tightening home appraisals, requiring that FHA lenders have audited financial statements, and increasing the capital requirement of FHA lenders to $1 million up from $250,000. The scandal is that these basic standards weren’t in place years ago.

Unfortunately, Washington won’t touch more significant reforms for fear of angering the powerful nexus of Realtors, mortgage bankers and home builders. As we’ve written for years, the FHA’s main lending problem is that it requires neither lenders nor borrowers to have a sufficient financial stake in mortgage repayment. The FHA’s absurdly low 3.5% down payment policy, in combination with other policies to reduce up-front costs for new homebuyers, means that homebuyers can move into their government-insured home with an equity stake as low as 2.5%. The government’s own housing data prove that low down payments are the single largest predictor of defaults.

Private banks know this. Burned on subprime mortgages, they are back to requiring 10% or even 20% down payments. Congress should at least require a 5% down payment on loans that carry a taxpayer guarantee. If borrowers can’t put at least 5% down, they can’t afford the house.

As for rooting out fraud that contributes to high loss rates, the obvious solution is to drop the 100% guarantee on FHA mortgages. Why not hold banks liable for the first 10% of losses on the housing loans they originate, a reform that has been recommended since as far back as the early Reagan years? No other mortgage insurer insures 100% loan repayment. Alas, while offering its minireforms, the Obama Administration reassured its real-estate pals that FHA insurance will continue to carry “no risk to homeowners or bondholders.”

Which means all the risk is on taxpayers. David Stevens, the FHA commissioner, nonetheless declared this month: “There will be no taxpayer bailout.” That’s also what Barney Frank said about Fannie and Freddie.