Introduction: Gynecologic cancers pose significant challenges due to the specialized care required for treatment. In 2023, approximately 114,810 new cases of gynecologic cancers were diagnosed in the U.S., with 34,020 related deaths. Health insurance plays a pivotal role in determining access to specialized oncologic care, and disparities in coverage often translate to disparities in cancer outcomes. In California, the state's diverse population and varying insurance market complicate access to care. Public insurance programs like Medi-Cal often provide limited access to specialized care, which may exacerbate health disparities across racial, ethnic, and socioeconomic groups. This study aims to characterize variations in California insurance coverage networks and assess how they impact access to gynecologic oncologic care.

Methods: Data were collected from major insurance providers, including Medi-Cal, Covered California, Medicare Advantage, and commercial insurers. Insurance network data were analyzed to determine the availability of gynecologic oncologists across California. Geographic analysis was conducted using census data to map the distribution of care across the state and identify regions where women are most likely to lack access to specialty care due to insurance network constraints. Disparities based on racial, ethnic, and socioeconomic groups were also examined to understand how these factors impact access and treatment outcomes.

Results: Our analysis revealed gaps in access to gynecologic oncology care across California, primarily influenced by insurance coverage and geographic distribution. We identified that many insurance networks, including some offered by major providers like Medicare Advantage, Medi-Cal, and certain marketplace plans (Covered California), do not consistently include gynecologic oncologists within their in-network provider lists. Smaller, narrow networks Covered California were more likely to exclude specialized physician care. Geographically, the disparities in access to gynecologic oncologists are pronounced. Urban areas, such as Los Angeles and the San Francisco Bay Area, have a relatively higher concentration of gynecologic oncologists, with most major insurance plans offering in-network access to specialists. Even in urban areas like Los Angeles and the Bay Area, certain local insurance plans with strict referrals requirements and prior authorizations, may limit care despite the availability of local gynecologic oncologists. In contrast, commercial insurers in these areas more frequently offer direct access to these specialists. However, rural areas, such as the Central Valley and the Inland Empire, exhibit more sparse access to care. For example, in the Central Valley and Inland Empire, the ratio of gynecologic oncologists to women was as low as 1 per 200,000. In contrast, urban centers like San Francisco had a higher concentration of gynecologic oncologists, with ratios of approximately 1 per 83,000 women.

Conclusion: The findings of this study underscore significant disparities in access to gynecologic oncology care across California, driven by both insurance network limitations and geographic factors. Narrow insurance networks, especially in public insurance and marketplace plans like Medi-Cal and Covered California, do not consistently include gynecologic oncology specialists, creating barriers to timely and affordable care. The consequences of this lack of in-network access are profound: delayed referrals, postponed treatments, and increased out-of-pocket costs that disproportionately affect underserved populations.