Exploring the decline of narrow networks on the 2017 ACA marketplaces.

The prevalence of narrow provider networks on the ACA Marketplace is trending down. In 2017, 21% of plans had narrow networks, down from 25% in 2016. The largest single factor was that 70% of plans from National carriers exited the market and these plans had narrower networks than returning plans. Exits account for more than half of the decline in the prevalence of narrow networks, with the rest attributed to broadening networks among stable plans, particularly among Blues carriers. The narrow network strategy is expanding among traditional Medicaid carriers and remains steady among provider-based carriers and regional/local carriers.