Access to primary health care is a major public health issue in France. The Localized Potential Accessibility (LPA) indicator, considered the benchmark indicator for identifying underserved areas, provides an indirect measure of the imbalance between health care supply and demand. The aim of this study is to propose a complementary indicator, based on general practitioners’ acceptance of new patients, in order to better characterize territorial inequalities in access to primary care.

We use original data collected from online medical appointment-booking platforms, covering nearly 12,000 general practitioners and more than two-thirds of the French population. At the municipal level, we compute the Proportion of general practitioners accepting New Patients (PNP), using a methodology comparable to that employed for the LPA.

Territorial disparities appear more pronounced when measured using the PNP than when measured using the LPA. Across the different measures of dispersion considered, territorial heterogeneity is two to three times higher with the PNP. Substantial discrepancies are observed between the two indicators: for 8.61% of municipalities (15.35% of the population), the LPA underestimates difficulties in accessing primary care, whereas for 11.19% of municipalities (22.28% of the population), it overestimates them relative to the PNP.

The PNP constitutes a direct and concise indicator of the imbalance between health care supply and demand. Complementary to the LPA, it enables a more refined identification of underserved areas and improves the targeting of public policies aimed at reducing territorial inequalities in access to primary care. These findings support broader collection and systematic use of the PNP as a central criterion for analyzing supply–demand imbalances and as a tool to guide public policy targeting.