Geographic Disparities in Oncology Access: A National Geospatial Analysis of Workforce Distribution and Fellowship Expansion

Purpose Geographic disparities in access to oncology care in the United States persist because of the maldistribution of oncologists and training programs. The aim of this study was to identify optimal oncologist placements to maximize coverage, detect large clusters of unmet patient need, and evaluate factors associated with new oncology fellowship program establishment. Methods We performed a national geospatial analysis from 2015 to 2025 using data from the Centers for Medicare & Medicaid Services, the National Resident Matching Program, and the US Census. A maximal coverage location problem (MCLP) model with a 40-km service radius identified optimal oncologist placements. Hierarchical density-based clustering found geographic clusters of unmet need. A Firth logistic regression model assessed county-level predictors of new fellowship program establishment. Results Median baseline state-level oncologist coverage was highest in the Northeast and lowest in the Midwest and South. The MCLP model identified 5,578 additional oncologist placements that could extend coverage to 26.1 million patients aged 55 years and older; 52.2% of placements were in rural counties. Clustering revealed 910 areas of unmet need, including large underserved populations in Nevada, California, and Florida. Oncology fellowship programs increased from 140 to 180 between 2015 and 2025, with minimal rural growth (0.6%-1.7%). Higher income, greater oncologist density, and Medicaid expansion predicted new program establishment, while rurality was strongly negatively associated. Conclusion Significant geographic disparities in oncology access remain. Targeted workforce expansion, particularly in rural areas, could improve coverage; however, current fellowship growth patterns risk reinforcing existing inequities. Strategic, data-driven expansion of oncologists and training programs is needed to promote equitable cancer care access.