Indiana University-Purdue University Indianapolis (IUPUI) / Oral health is crucial to overall health and a focus of the U.S. Health Center program, which provides preventive dental services in medically underserved communities. Dental hygiene is an oral health profession whose practice is focused on dental disease prevention and oral health promotion. Variations in the practice and regulation of dental hygiene has been demonstrated to influence access to dental care at a state level; restrictive policies are associated lower rates of access to care. Understanding whether and to what extent policy variations affect availability and access to dental care and the oral health of medically underserved communities served by grantees of the U.S. Health Center program is the focus of this study. This longitudinal study examines dental service utilization at 1,135 health center grantees that received community health center funding from 2004 to 2011. The Dental Hygiene Professional Practice Index (DHPPI) was used as an indicator of the state policy environment. The influence of grantee and state level characteristics are also considered. Mixed effects models were used to account for correlations introduced by the multiple hierarchical structure of the data. Key findings of this study demonstrate that state policy environment is a predictor of the availability and access to dental care and the oral health status of medically underserved communities that received care at a grantee of the U.S. Health Center program. Grantees located in states with highly restrictive policy environments were 73% less likely to deliver dental services and, those that do, provided care to 7% fewer patients than those grantees located in states with the most supportive policy environments. Population’s served by grantees from the most restrictive states received less preventive care and had greater restorative and emergency dental care needs. State policy environment is a predictor of availability and access to dental care and the oral health status of medically underserved communities. This study has important implications for policy at the federal, state, and local levels. Findings demonstrate the need for policy and advocacy efforts at all levels, especially within states with restrictive policy environments.