The Federal Housing Finance Agency acting director, Edward DeMarco, recently sent to Congress a strategic plan for the next phase of conservatorships of Fannie Mae and Freddie Mac. A new structure for housing finance requires congressional action, yet neither Congress nor the administration has come up with an acceptable plan in the three years since Fannie and Freddie were placed into conservatorship. It's far from clear that the DeMarco plan will get the job done.

Fannie and Freddie have received more than $180 billion in taxpayer support during the last three years, and taxpayers are likely to be on the hook for twice that amount before we're done. We need a plan that will preserve the value that currently exists with the agencies in order to minimize the taxpayer cost and one that never places taxpayers at risk again.

Subprime mortgages have existed for decades. But they were a small percentage of the mortgage market (well under 10 percent), until Fannie and Freddie reduced credit standards to increase market share and meet low income and minority home ownership targets mandated by Congress. By 2007 nearly 50 percent of all mortgages originated in the U.S. were subprime with Fannie, Freddie and other agencies guaranteeing about 70 percent.

Without these government guarantees, the subprime bubble and the resulting financial crisis would never have happened. Bank regulators and industry experts warned Congress for decades about Fannie and Freddie and their increasingly large and risky portfolios.

Because Congress failed to act, nearly the entire developed world is suffering from the mortgage-induced recession. Taxpayers are on the hook for hundreds of billions of dollars of losses at Fannie and Freddie – dwarfing the losses from banks, Wall Street, auto companies, insurance companies and all other bailouts combined.

We don't understand why reform of Freddie and Fannie is taking so long and what all the angst is about. The solution is straightforward: the public/private hybrid of Fannie and Freddie should be abolished, their existing business sold or liquidated, and the mortgage market privatized.

This can be done in an orderly way in a few easy steps. Fannie's and Freddie's existing portfolio of mortgages should be sold at a rate of about $75 billion a year until it reaches zero. The current $625,000 size limit on new mortgages guaranteed by Fannie and Freddie should be reduced by $100,000 per year, so that Fannie and Freddie would be out of the guarantee business within six years. The liability for any outstanding guarantees would be managed by the current government conservatorship of Fannie and Freddie until they run off or are sold.

If the government still wants to be in the mortgage business for low income families or minorities, it should be on budget and transparent. There already exists a government organization to do this – the Federal Housing Administration.

Some say this would put at risk the American dream of home ownership. We disagree. The United States is the only major country in the world where the government is heavily involved in the mortgage market. Yet, home ownership percentage in the United States is only slightly higher (a percent or two) than most other developed countries, while countries like Canada have higher percentages than the U.S.

Some speculate that without Fannie and Freddie mortgage rates would skyrocket and the 30-year, fixed-rate mortgage would be a thing of the past. We disagree. Non-conventional or "jumbo" 30-year mortgages not guaranteed by Fannie and Freddie have existed for decades.

In the decade preceding the financial crisis, the interest rate on these jumbo non-conventional mortgages averaged just one quarter of one percent higher than similar guaranteed mortgages, a difference of a little over $40 a month on a $200,000 mortgage. Shouldn't Americans, like homeowners throughout the world, pay a tax-deductible $40 or so extra per month so taxpayers aren't on the hook for hundreds of billions to bail out Fannie and Freddie?

It's clear that we need to abolish the public/private mortgage model as represented by Fannie and Freddie. The U.S. mortgage market should be privatized, as it is in other developed countries.

It's time for Congress to do what it should have done decades ago and give the FHFA a clear roadmap so that they can manage this process at the least cost to the taxpayer and with a smooth transition to the private sector. Get the government out of the mortgage business so taxpayers are never again at risk.

Richard M. Kovacevich is the retired chairman and CEO of Wells Fargo & Company. William M. Isaac, former chairman of the Federal Deposit Insurance Corporation, is senior managing director and global head of financial institutions at FTI Consulting, chairman of Fifth Third Bancorporation, and author of Senseless Panic: How Washington Failed America. The views expressed are their own.