Long-term care (LTC) costs create burdens on aging societies. Maintaining oral health through dental visits may result in shorter LTC periods, thereby decreasing LTC costs; however, this remains unverified. We examined whether dental visits in the past 6 months were associated with cumulative LTC insurance (LTCI) costs. This cohort study of the Japan Gerontological Evaluation Study targeted independent adults aged ≥65 years in 2010 over an eight-year follow-up. We used data from a self-reported questionnaire and LTCI records from the municipalities. The outcome was cumulative LTCI costs, and exposure was dental visits within 6 months for prevention, treatment, and prevention or treatment. A two-part model was used to estimate the differences in the predicted cumulative LTCI costs and 95% confidence intervals (CIs) for each dental visit. The mean age of the 8,429 participants was 73.7 years (standard deviation [SD]=6.0), and 46.1% were men. During the follow-up period, 17.6% started using LTCI services. The mean cumulative LTCI cost was USD 4877.0 (SD=19082.1). The predicted cumulative LTCI costs were lower among those had dental visits than among those who did not. The differences in predicted cumulative LTCI cost were -USD 1089.9 (95%CI = -1,888.5 - -291.2) for dental preventive visits, -USD 806.7 (95%CI = -1,647.4 - 34.0) for treatment visits, and -USD 980.6 (95%CI = -1,835.7 - -125.5) for preventive or treatment visits. Dental visits, particularly preventive visits, were associated with lower cumulative LTCI costs. Maintaining oral health through dental visits may effectively reduce the LTCI costs.