Business process outsourcing (BPO) vendors are becoming increasingly verticalized by industry. For example, there are now over 20 BPO vendors for the mortgage lending industry. While some lenders have been offshoring for a few years, other lenders are still determining what processes to offshore. Outsourcing vendors are trying to determine how the size of their potential revenue market. This TowerGroup Research Note highlights the US mortgage industry cost issues that drive demand for offshore BPO services, estimates the size of the offshorable mortgage market, and forecasts the size of the addressable market, which is a measure of revenue opportunity for BPO providers.