BACKGROUND: Electronic health record (EHR) transitions can cause major disruptions in the provision of primary care services. Veteran Health Administration (VHA), one of the largest integrated healthcare systems, underwent a major EHR transition at two sites. To date, there is limited data on the experience of primary care service lines at EHR transition sites. OBJECTIVE: To describe and quantify changes in the provision of primary care services at two sites that have experienced EHR transition. DESIGN: We conducted a retrospective study of primary care encounters 12 months before and after EHR transition. In addition, we applied economic structural change analysis using the expanded length of time (10 years of prior primary care encounters at sites) to understand how the transition of EHR compares to other major changes in primary care encounter volume during this time period. DATA SOURCE AND MAIN MEASURE: Primary care encounters were measured using algorithms pre- and post-EHR transition from the national VHA Corporate Data Warehouse (CDW) and Cerner Millennium (CDW2) Databases. KEY RESULTS: In Spokane, the average number of monthly primary care encounters decreased from 7155 (SD = 682) in the 12 months prior to October 2020 (transition date) to 4181 (SD = 813) in the 12 months after implementation, a decrease of 41.6 %. The average number of monthly primary care encounters decreased from 8029 (SD = 511) in the 12 months prior to April 2022 (transition date) to 6495 (SD = 1152) in the 12 months after implementation, a decrease of 19.1 %. The structural change analysis identified EHR transition dates at both sites, including a major decrease in volume of primary care encounters. CONCLUSIONS: Given the substantial decrease in primary care services, VHA must identify strategies to mitigate both the amount and the duration of reduced primary care encounters during the EHR transition.