Quality Regulation? Access to High-Quality Specialists for Medicare Advantage Beneficiaries in California.

Medicare Advantage enrollment has seen tremendous growth over the past decade. However, we know comparatively little about the experience of beneficiaries in the program. Our knowledge of Medicare Advantage provider networks is particularly limited. This article is one of the first major assessments of the issue. It seeks to answer 3 important questions. First, are Medicare Advantage plan networks made up of higher quality providers? Second, how significant are the network restrictions imposed by Medicare Advantage plans with regard to access to higher quality providers? And finally, how much provider choice are Medicare Advantage beneficiaries left with? To assess these questions, I utilize geospatial data and individual provider quality measures for cardiologists, endocrinologists, and obstetricians and gynecologists from California. I find that Medicare Advantage beneficiaries generally do well in large metropolitan areas compared to traditional Medicare. However, there are concerns for those in micropolitan and rural areas, and even those in standard metropolitan areas, at times. Crucially, the connection between provider quality and networks can only be fully understood when connected to assessments of provider access. These findings also raise questions about how we think about provider networks and the adequacy of current approaches to network regulation.