Hospital and Physician Networks in US Insurance Markets

The Journal of the American Medical Assn. (JAMA) provided (to their knowledge) the first national snapshot of the size and exclusivity of health insurance networks across all markets. JAMA examined network variation among insurance types, including employer-sponsored insurance, Medicare, and Medicaid. 

They found that many patients can switch to a lower-cost, narrow network plan without losing in-network access to their PCP. Narrow health care networks can still have sizeable overlap with other area networks. In many states, narrower networks have as much, if not more, overlap across different insurers’ networks than the broadest networks. Narrower and more exclusive networks are found in areas with less concentrated markets for insurance, physicians, and hospitals. 

It may seem counterintuitive, but large networks can also be exclusive. Seventy-five percent of local physicians could contract exclusively with a single insurer while the remaining 25% contract with a variety of different insurers. In many states, the broadest networks have less overlap with other networks in the same area. 

Areas with high insurer and (especially) physician and hospital market concentration have broader and less exclusive networks. The most exclusive networks are in the most competitive market environments. 

Researchers say that a more holistic picture of networks is needed to understand the implications for care continuity because switching between insurance plans not only occurs within an insurance type but between them.