This report describes preliminary work in support of an early childhood needs assessment for American Indian and Alaska Native (AI/AN) children prenatal to age five. The report presents the process and findings from implementing Design One--describing the population of AI/AN children and families and their participation in early childhood services based on "existing data sources"--with a set of national survey and Administration for Children and Families (ACF) administrative data sources. Implementation of Design One followed three steps: (1) a review of six data sources to identify data elements addressing the key indicators; (2) a review of published information from the four of those data sources for which published information was available; and (3) secondary analysis of two of the data sources. Findings from the report include: (1) The selected data sources have the potential to address AI/AN Early Childhood Needs key indicators of policy and programmatic interest--with data items available on 62 of 87 key indicators across all 9 research questions; (2) Little information, however, has been published to date--17 of the 62 key indicators potentially available were found in published information (covering 7 research questions); (3) New analysis focusing on the key indicators can expand the extent of information known--analysis of the American Community Survey and Head Start Program Information Report addressed 43 key indicators from 8 of the 9 research questions; and (4) Use of existing data can present challenges in goodness of fit in how well existing data (collected for a different purpose and across different times) align to the key indicators and intent of the research question.