The Federal Housing Finance Agency is reviewing four possible options to update the credit scoring systems used by Fannie Mae and Freddie Mac. The agency said while the current credit score model is a reasonable predictor of default, it is seeking input on whether an alternative is necessary and what impact it would have on the current credit score requirements. The request for input was issued in late December. Options include requiring a single type of score on every loan, requiring two different scores, allowing lenders to decide which score to use or permitting multiple scores through a waterfall approach.