This article examines how the U.S. monetary policy surprises impact the mortgage rates in the nation and across five regions from 1990 to 2008. Regression analysis based on bootstrapping shows that surprises in the target federal funds rate (the target factor) have a significantly positive impact on the 1-year adjustable-rate mortgage (ARM) rate within the week of the Federal Open Market Committee announcements and the positive impact lasts up to 1 week after the announcements. Surprises in the future direction of the Federal Reserve monetary policy (the path factor) have significantly positive impacts on both the 1-year ARM rate and the 30-year fixed mortgage rates in the first week after the announcement. Furthermore, the responses of mortgage rates are asymmetric and affected by the size of monetary policy surprises, the stage of the business cycle and whether the monetary policy is tightening or loosening. There also exists heterogeneity in the mortgage rate pass-through process across regions and monetary policy surprises have differential impacts on the regional mortgage rates. The cross-region variations are mainly correlated with the regional housing market conditions, such as home vacancy and rental vacancy rates.