In 2015, the Administration for Children and Families funded a new study--the Migrant and Seasonal Head Start Study (MSHS Study)--to focus on MSHS programs and the families they serve. The MSHS Study is designed to closely match the characteristics of the whole population of MSHS programs, centers, families and children across the United States (a "nationally representative study"). Since the last nationally representative study of MSHS was conducted almost 20 years ago, this study provides a much-needed update on MSHS programs and centers, as well as the migrant and seasonal farmworker families they serve. (author abstract)