Importance Dental surgery under general anesthesia (DGA) is an ineffective, costly treatment for caries. Interventions to reduce the need for DGA are challenging because children’s parents may not seek care until surgery is required. Community water fluoridation (CWF) effectively prevents early childhood caries, but its effectiveness in reducing severe early childhood caries is unknown. Objective To determine whether access to CWF is associated with the prevalence of DGA. Design, Setting, and Participants This is a cross-sectional analysis of Medicaid claims data from 2011 to 2012. Deidentified data were derived from Medicaid claims and enrollee files for Massachusetts, Texas, Connecticut, Illinois, and Florida for children aged 9 years and younger enrolled in either a fee-for-service or managed care plan through their state’s Medicaid program. Linear regression models tested for associations between CWF and covariates. Multivariable linear regression models tested for associations between CWF and outcomes. Regression models included clustered SEs at the county level. Data analysis was performed from December 2018 to March 2020. Exposures Access to CWF was determined by estimating the proportion of a county’s total population that had access to a fluoridated public water system. Main Outcomes and Measures The main outcome was county-level DGA prevalence. Other outcomes were caries-related visit prevalence and patient quality indicators (asthma and diabetes). Covariates included county-level demographic, socioeconomic, and dental practitioner variables. Results A total of 436 counties within 5 states per year (872 county-year observations), were included in the analysis. Adjusted analysis revealed that a 10% increase in the proportion of county’s population access to CWF was associated with lower caries-related visit prevalence (−0.45 percentage points; 95% CI, −0.59 to −0.31 percentage points; P < .001). Increasing CWF access in 10% increments was associated with decreased DGA prevalence in unadjusted analysis (−0.39 percentage points; 95% CI, −0.67 to −0.12 percentage points; P = .006) but not in adjusted analysis (−0.23 percentage points; 95% CI, −0.49 to 0.02 percentage points; P = .07). Increasing the proportion of county’s access to CWF by 10% was not associated with the prevalence of asthma-related exacerbations (−0.02 percentage points; 95% CI, −0.10 to 0.05 percentage points; P = .53) or diabetes-related exacerbations (−0.0003 percentage points; 95% CI, −0.0014 to 0.0009 percentage points; P = .66). Conclusions and Relevance This study extends our understanding of CWF’s benefits for children’s oral health. Specifically, these findings suggest that increasing a population’s access to CWF’s is associated with decreased caries-related visits and may also be associated with use of dental surgical services within high-risk populations.