The fast-growing prevalence of Parkinson's disease (PD) creates a heavy burden for society and the health care system. Although different ways to mitigate the economic burden of PD have been discussed in the literature, including several effective treatments, few studies have paid attention to the effect of care rehabilitation (CR) on PD costs over a long-term care period. This study tracked medical expenses, care costs, and total costs of elderly individuals with PD for 3 years based on medical claims data merged with long-term care insurance (LTCI) claims data, and determined whether CR reduced PD costs. Using a retrospective, longitudinal cohort design, 3950 elderly individuals with PD who received LTCI services from April 2014 to March 2017 in Fukuoka Prefecture, Japan were followed. PD costs were compared between the CR group and the non-CR group, and a hierarchical linear model was used to examine whether CR was associated with medical expenses, care costs, and total costs. The mean value of total costs in fiscal years 2014, 2015, and 2016 were ¥3,124,944 (US$29,504), ¥3,328,398 (US$31,425), and ¥3,615,892 (US$34,140), respectively. In a hierarchical linear model, CR alone was not associated with medical expenses and care costs; additionally, CR had a positive association with higher total costs. However, the interaction term between CR and baseline care needs level significantly reduced care costs and total costs. That indicates that if older PD patients with higher care needs level receive CR, their care costs and total costs will be reduced. Further research is needed to clarify how CR reduces these patients' costs.