Objectives The patient centered medical home is now widely supported as a strategy for delivering high quality primary care. The objective of this study was to examine whether children's primary care experiences nationally have become more aligned with the medical home model over time, and how this may have varied for vulnerable children. Methods This study analyzed data on 289,672 children, aged 0-17 years, of families responding to one of three iterations of National Survey of Children's Health from 2003, 2007 and 2011-2012. Each year, we assessed indicators of four medical home features (access, continuity, comprehensiveness, and family-centeredness) and a total medical home score for children nationally and for those with a set of social and demographic risk factors. Results Indicators of access and continuity, and total medical home scores fluctuated but improved overall from 2003 to 2012 (7.1, 6.7 and 1.4 % point increases, respectively), while indicators of comprehensiveness and family-centered care measures declined (2.4 and 1.8 % point decreases, respectively). Children with the highest levels of social and demographic risk experienced larger fluctuations in these measures over time. Conclusions for Practice There were improvements in the extent to which children's primary care experiences aligned with a medical home model, though not linearly or for all component features. Children with more risk factors experienced more volatile changes, suggesting a particular need to attend to the primary care experiences of the most vulnerable children.