The document provides an overview of the Boundary and Annexation Survey (BAS), which collects annual information from local governments about boundary changes. It discusses why the BAS is conducted, who benefits, how governments can respond, important dates, and state certification of reported changes. The key points are: - The BAS collects boundary and annexation information to ensure accurate Census data and maps. - Local governments, states, and other agencies benefit from more precise geographic assignments and statistical tabulation. - Governments can respond on paper forms or digitally using provided GIS tools by deadlines in March or May. - States review submitted changes for legal compliance through the certification program.