President Barack Obama unveiled plans to help 7 million to 9 million families restructure or refinance their mortgages, warning that the housing crisis could stretch far beyond troubled homeowners if unaddressed.

"In the end, all of us are paying a price for this home mortgage crisis," Obama will say in a speech in Phoenix on Wednesday. "And all of us will pay an even steeper price if we allow this crisis to deepen - a crisis which is unraveling homeownership, the middle class and the American Dream itself."

The broad features of the plan emerged Wednesday morning: a new $75 billion homeowner stability initiative designed to reach 3 million to 4 million at-risk homeowners, refinancing for up to 4 million to 5 million responsible homeowners and new capital for Fannie Mae and Freddie Mac.

Addressing concerns that the plan could be exploited by homeowners who took risky bets on the housing market, Obama said it will focus on those who "played by the rules." People whose traditional mortgages are "underwater" will be eligible for refinanced loans, while people with subprime mortgages will be able to modify their loans.

"I also want to be very clear about what this plan will not do: It will not rescue the unscrupulous or irresponsible by throwing good taxpayer money after bad loans," Obama said.

Obama said that any financial firms receiving, or hoping to receive, taxpayer financial assistance through the Troubled Asset Relief Program would have to agree to modify their loan books along the guidelines established in the housing proposals. Under the plan, the federal government would cover half the losses incurred by lenders that work with borrowers to reduce their monthly payments.

Lenders would be required to reduce those payments to no more than 31% of a borrowers' income.

-By Henry J. Pulizzi, Dow Jones Newswires; 202-862-9256; henry.pulizzi@dowjones.com