But that could cost you more than $1,000 a year in higher mortgage interest payments, and make it tough to find a 30-year fixed-rate loan when you want to refinance or buy. After all, Fannie Mae, Freddie Mac, and the FHA guarantee almost 90% of U.S. mortgage loans.
   
We looked at two hypothetical families—the Smiths and the Joneses, who each buy a $200,000 home with a 20% downpayment—and calculated how different their financial picture would be if one family didn’t have a government-backed loan.

Our scenario assumes a 1 percentage point difference in the two families’ loan rates. Some experts believe a 1% difference is conservative and would be even higher in a world without Fannie Mae or Freddie Mac guarantees.