Two federal offices have come to radically different conclusions about the fiscal impact of the Zero Downpayment Act of 2004, a proposed law that would authorize the FHA to insure mortgages for first-time home buyers who can afford a house payment but lack a down payment. The Office of Management and Budget reported earlier this year that the program would generate almost $200 million a year in FHA premiums. This summer, however, the Congressional Budget Office (CBO) reported the act would cost the federal government more than $100 million a year, based on a prediction that a high percentage of the borrowers would default on their loans. Supporters of the bill (H.R. 3755) admit the report doesn't help its chances of passage and are asking the CBO to take another look at its numbers.