A Kaiser Family Foundation analysis of private Medicare plan networks finds that Medicare Advantage plans include about  half of area hospitals in their network, on average, while one in five plans have no  Academic Medical Center in-network.  Among plans in an area with a National Cancer Institute-designated cancer center, more than two in five did not include the cancer center in their network.

The new study of the hospital networks of Medicare Advantage plans, which includes plan and firm-specific information for 409 plans in a geographically diverse sample of 20 counties in 2015, also finds that information about hospital networks is not readily available, sometimes inaccurate and rarely consumer friendly.  More than 17 million of Medicare’s 57 million beneficiaries are enrolled in Medicare Advantage plans, and enrollment in the private plans is projected to reach 30 million by 2026.

The analysis finds the size of hospital networks varies across Medicare Advantage plans. Almost a quarter of Medicare Advantage plans (23%) had broad networks, defined as including 70 percent or more of area hospitals, while about one in six plans (16%) had narrow networks, defined as those with fewer than 30 percent of hospitals in the county. Among HMOs, which comprise 75 percent of the plans in the study, premiums vary little by network size, with broad and narrow network plans having similar average monthly premiums of $37 and $36, respectively.

The majority of plans included at least one of their county’s Academic Medical Centers and one in five plans did not. Similarly, at least two in five (41%) Medicare Advantage plans did not include their county’s National Cancer Institute (NCI)-designated cancer center (among the counties with a cancer center). Academic Medical Centers are more likely to have physicians specializing in rarer conditions and complex medical conditions, and are more likely to conduct surgeries, such as heart surgery, for which better outcomes have been linked to higher volumes.  Access to NCI cancer centers may be particularly relevant to beneficiaries with rarer cancers, more advanced-stage cancers, or other unique complicating conditions.

For Medicare Advantage enrollees who place a high value on access to a specific hospital in their area, the analysis underscores the importance of shopping carefully for a plan and the difficulties in doing so. Provider directories are not posted on the Medicare.gov “plan finder” tool, which is a government-sponsored resource to help consumers shop for plans available in their area. Provider directories obtained directly from the plans can be confusing or outdated. For instance, 11 of the 231 provider directories examined in this study included hospitals that had been closed or torn down.