This report describes the sample design for the 2002 National Survey of America's Families (NSAF). This survey is the third round of the NSAF, and the objective is to estimate both the characteristics of households and persons in 2002 and changes in those characteristics since the 1997 and 1999 NSAF. While the designs for all three rounds of the NSAF are similar, several important differences exist. This report describes how the 2002 sample design relates to the designs from previous rounds. It also provides the details needed to appreciate the considerations that went into the decisions that resulted in the features of this large and complex survey.