Data can play an important role in improving health care systems. The state-based marketplaces established under the Affordable Care Act (ACA) are well positioned to advance policy decisions by disclosing detailed information about enrollment. Such information could improve oversight of the post-ACA insurance market, and help policymakers and others more easily identify areas where consumers could be better served.

However, to date, the 17 state-based marketplaces have released varying degrees of information, with some marketplaces providing very little public data about enrollment by insurance carrier or health plan, or about enrollee demographics.

Marketplace Metrics: Little Consensus About What Data to Report

Although all state-based marketplaces publicize top-line enrollment numbers, there is little consistency across states in the other data categories reported. California makes available a range of mostly downloadable data—including how enrollees access the marketplace by income, and metrics such as subsidy status and customer support experience by ethnicity—but other states supply next to nothing. Less than half of states provide demographic data on enrollees and the proportion of new enrollees compared with renewals, while fewer states break down enrollment by carrier, plan, or location (Exhibit 1). The federal marketplace releases data on most of these metrics, although it does not share enrollment by carrier or plan.

About half of all state-based marketplaces provide statistics about the level of service that their consumers receive, including, for example, information on call-center wait times. But states vary so much in terms of the types of data they offer that making robust comparisons across state-based marketplaces on many of these metrics is difficult to impossible.

Data Releases Vary in Frequency and Form

State-based marketplaces also vary in terms of how they release information. Some states, such as Colorado and Massachusetts, provide easily accessible and regularly updated online data dashboards. This approach has numerous advantages. Policymakers and stakeholders have access to a consistent set of state data that can be used to measure outcomes over time. Other marketplaces, like Minnesota's and Washington's, produce similarly helpful dashboard-style enrollment data, but disseminate them only through marketplace board meeting materials.

Other state-based marketplaces provide enrollment updates via press release. While regular releases, like the weekly announcements produced by the Maryland Health Connection, can keep policymakers and stakeholders up-to-date on enrollment progress, others states provide such information only intermittently. Moreover, in practice, these communications often contain only top-level information.

Some states also provide detailed enrollment data through annual reports. While such reports are useful, practices in other states and for other federal programs suggest value in more frequent disclosures. For example, Washington provides reports before and after open enrollment while the U.S. Department of Health and Human Services (HHS) provides data on enrollment through the federally facilitated marketplace several times a year. For Medicaid, HHS has shown it can be quicker still, publishing enrollment reports monthly.

Seizing the Opportunity to Inform the Debate

It’s clear that more opportunities for learning about marketplace enrollment remain. Marketplaces could provide disaggregated, plan-level enrollment data by premium rating region, which would allow researchers and other stakeholders to locate and understand patterns in consumer behavior, such as why consumers move between plans and different coverage levels. Researchers could look at how different factors interact, helping them understand how changes in a plan’s network or premium affect consumer choices. The availability of such data also could help determine, for example, if people with chronic conditions enrolled disproportionately in particular kinds of plans, an indicator of uneven risk selection among plans.

Improved demographic data can highlight which communities are in need of improved outreach, while enrollment data by carrier and plan can reveal the market power of carriers and patterns of consumer decision-making. In touting Covered California’s new data mining project, Executive Director Peter Lee noted that the marketplace shared data with university researchers who were able to compare enrollment data against other sources to show that new enrollees were healthier. Covered California then used this information to negotiate lower premiums from insurers.

Given that the marketplaces have gone through only two open enrollment periods, it remains to be seen how policymakers and stakeholder organizations can leverage marketplace data to offer additional products and services that can help consumers navigate complicated insurance markets. But more and better data could only help marketplaces and stakeholders cover more people and ensure that consumers are getting the coverage that is right for them. State-based marketplaces are likely collecting this data internally, and could do much to inform the conversation about how health reform is working by making this information publicly available.