Background/Objective: As healthcare expenditures continue to increase worldwide, strategies are needed to ensure healthcare is delivered in an efficient and sustainable way. One of the prominent strategies based on a construct of primary care, is continuity of care (COC) reflecting long-term patient-provider relationships, and greater knowledge of patient’s medical conditions. In this study, we exploit rich clAims data to study the causal effect of longitudinal COC on healthcare costs by analyzing the effect of moving to a region with better COC. Methods: We used data on 240’000 insured individuals aged 50+ in 2015-2018, obtained from one of the largest Swiss health insurance company. We calculated Bice-Boxerman index of COC in primary care based on visits to the general practitioners (COC GP). To identify the causal effect of COC on costs, we estimate individual fixed-effects models and exploit the fact that some individuals move across regions. Results: The COC GP varied from 0.86 to 0.92, while mean total costs varied from 9768 CHF to 8,129 CHF (highest vs. lowest COC tercile). The model Results, controlling for 10-year age bins, calendar year fixed effects, morbidity status, deductibles level, and type of insurance model showed that the move to a region with higher COC GP Resultsed in decrease of 1’817 CHF in total, 1,059 CHF in ambulatory, 409 CHF in inpatient, and 395 CHF in costs of medicaments. Conclusions: Better COC Results in lower cost– this is an especially important finding in a highly fragmented health care systems like Switzerland, and in view of upcoming policy Discussions to implement generalized gatekeeping in the country. As COC is a multifaceted construct, future research and policy-makers should obtain additional evidence on informational COC (e.g., electronic health records promotion and effective management). The mechanisms behind the effects identified in this work should also be further investigated.