Fannie Mae last month implemented changes to its Desktop Underwriter program following a surge in acquisition mortgages with high debt-to-income ratios that caused an uproar with some private mortgage insurers. In July 2017, the GSE revised its underwriting guidelines to accept DTI ratios over 45 percent without requiring lenders to show compensating factors. As previously reported by Inside The GSEs, the change led to a surge in high-DTI activity in the second half of 2017. Fannie Mae and Freddie Mac securitized $52.90 billion of mortgages with DTI ratios ranging from 46 percent to 50 percent, a 72.6 percent increase from the first six months of the year.