The Issue

More older Americans are enrolling in Medicare Advantage (MA) — the private plan alternative to traditional Medicare. In 2017, 33 percent of Medicare beneficiaries were in MA plans, up from 22 percent in 2008. With the growing popularity of these plans, it’s becoming increasingly important for policymakers to understand their benefits and costs, and the quality of care they deliver. Recently, some policymakers have raised concerns that the provider networks MA plans use are becoming more restrictive over time, making it harder for enrollees to get care when they need it. In an article for Health Affairs, Commonwealth Fund–supported researchers used Medicare Part D claims data from 2011 to 2015 to examine how MA primary care physician networks have changed over time.

1.8% proportion of MA plans with narrow primary care networks in 2015

What the Study Found

  • Plans with so-called narrow networks account for a small and declining proportion of MA primary care product offerings, having dropped from 2.7 percent of all offerings in 2011 to 1.8 percent in 2015. Broad-network product offerings, in contrast, increased from 80.1 percent of the total in 2011 to 82.5 percent in 2015.
  • MA enrollment has gradually shifted to broad networks over time. In 2011, broad-network products accounted for 54.1 percent of enrollment; in 2015, they accounted for 63.9 percent.
  • Enrollees in narrow-network plans travel an average of 1.6 miles farther to see providers than enrollees in broad-network plans.
  • Narrow-network products, compared to both broad- and medium-network products, are more prevalent in areas with large populations, higher median household incomes, and higher ratios of physicians to patients. It may be easier in those urban areas to exclude physicians from networks than it is in rural areas, where there are fewer doctors.
  • Health maintenance organization (HMO) plans tend to have narrower networks than point-of-service (POS) or preferred provider organization (PPO) plans.
  • Narrow-network products are more common in less-concentrated MA markets.

The Big Picture

Concerns that narrow networks are restricting access to primary care may be unfounded, as the authors’ research suggests that primary care MA networks are becoming broader, not less broad. Moreover, the introduction of a claims-based method — as opposed to using provider directories — for measuring provider networks may help regulators validate networks submitted by insurers. Claims-based networks capture where beneficiaries actually receive care; provider directories, which are created by plans, do not account for the fact that some providers may not be accepting patients. In addition, provider directories are known to be prone to error, often including listings of providers who are no longer in-network or not practicing.

The Bottom Line

Despite concerns that the provider networks of Medicare Advantage plans are becoming increasingly restrictive and impeding beneficiaries from getting the care they need, the share of plans with broad primary care networks has increased over time, while the share of those with narrow networks has decreased.