Background: Changing locations disrupts the populations served by primary health care clinics, and such changes may differentially affect access to care for vulnerable populations.
Methods: Online geographic information systems mapping tools were used to define how the relocation of a family medicine center impacted access to care for black and Hispanic patients with chronic disease.
Results: Maps created from practice management data revealed a distinct shift in black and Hispanic patients with chronic disease being served in the new location.
Conclusions: Geographic information systems tools are valuable aids in defining changing service areas of primary health care clinics.