In support of the national implementation of the Home Health Care CAHPS® (HHCAHPS) Survey, the Centers for Medicare & Medicaid Services (CMS) conducted a Mode Experiment from September 2009 through January 2010 to determine whether patients respond differently to the survey based on different data collection modes (mail, telephone or a mixed-mode approach). Data from the Mode Experiment were used to support development of appropriate adjustments to control for mode effects during the national implementation of HHCAHPS. Mode Experiment data were also used to determine whether ratings of home health care varies by patient characteristics. The results of the HHCAHPS Survey mode experiment showed no significant differences in results based on survey mode. There were, however, differences in responses attributable to patient mix characteristics. Therefore, patient mix adjustments are made on HHCAHPS Survey results that are publicly reported using selected patient characteristics identified during the mode experiment, but no adjustments are being made for mode differences.