Objectives: To ascertain differences across states in children's oral health care access and oral health status and the factors that contribute to those differences. Study design: Observational study using cross-sectional surveys. Methods: Using the 2007 National Survey of Children's Health, we examined state variation in parents' report of children's oral health care access (absence of a preventive dental visit) and oral health status. We assessed the unadjusted prevalences of these outcomes, then adjusted with child-, family-, and neighbourhood-level variables using logistic regression; these results are presented directly and graphically. Using multilevel analysis, we then calculated the degree to which child-, family-, and community-level variables explained state variation. Finally, we quantified the influence of state-level variables on state variation. Results: Unadjusted rates of no preventive dental care ranged 9.0-26.8% (mean 17.5%), with little impact of adjusting (10.3-26.7%). Almost 9% of the population had fair/poor oral health; unadjusted range 4.1-14.5%. Adjusting analyses affected fair/poor oral health more than access (5.7-10.7%). Child, family and community factors explained similar to 1/4 of the state variation in no preventive visit and similar to 1/2 of fair/poor oral health. State-level factors further contributed to explaining up to a third of residual state variation. Conclusion: Geography matters: where a child lives has a large impact on his or her access to oral health care and oral health status, even after adjusting for child, family, community, and state variables. As state-level variation persists, other factors and richer data are needed to clarify the variation and drive changes for more egalitarian and overall improved oral health. (C) 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.