These SAS Programs created by National Cancer Institute (NCI) can perform selected data edits and create per-day and per-person summary variables from NHANES 2003-2004 accelerometer data. Users can modify these programs to apply alternate definitions of valid data, monitor wear periods, or activity bouts. A program is also available to convert data downloaded from ActiGraph accelerometers to the data layout used in NHANES so that the data preparation programs can be used on those data as well. Please note that intermediate level SAS programming skills are needed to modify the provided code and that only limited technical support is available from NCI. The SAS programs are available from the NCI website.