If Congress succeeds in cutting the corporate tax rate next year, the GSEs would have to write down their deferred tax assets by somewhere between $13 and $19 billion or face having to take a draw from the Treasury, according to estimates from Keefe, Bruyette & Woods. The House Republican tax reform plan proposes to lower the corporate tax rate from 35 percent to 20 percent. It would be the largest reduction in the corporate rate in the nation’s history. But KBW also said having to take a draw because of the DTA write-down may not be that big of a deal.