The purpose of this resource is to help researchers prepare for issues that may arise when using administrative data as the primary data source for a research project. This is the third in a series of resources related to the analysis of administrative data. The first resource, Developing Collaborative Partnerships with State Agencies to Strengthen Research Using Early Care and Education Administrative Data, provides considerations for building a strong partnership between researchers who want to analyze administrative data and the state partners who oversee the administrative data. The second resource, Determining the Feasibility of Using State Early Care and Education Administrative Data, is designed to help researchers and their state partners determine whether analyzing administrative data is feasible and appropriate for addressing their child care and early education research questions. Once researchers and state agency partners have determined that it is feasible to use administrative data to address a question of shared interest, then this third resource can be helpful in preparing to analyze the data. These resources have been designed for use by researchers who are new to the analysis of administrative data as well as seasoned researchers who are expanding their research to include new types of administrative data or expanding into new states or new agencies. The information generated for each of these resources was developed through conversations with grantees and researchers who have experience analyzing state administrative data.