One thing that means is that while you could have solid national numbers in terms of enrollment demographic mix and so forth that could mask success in some states and market failure in others. It can't be emphasized enough that there is no national health insurance market. All the key numbers are only truly relevant within each states plans and risk pools.
A few takeaways. The top five states, judged by percentage of enrollees out of the eligible population for both private and Medicaid coverage, are: Vermont (37%), Washington state (30%), Rhode Island (21%), Kentucky (19%) and Connecticut (18%).
Now, in the words of Sesame Street, one of these states is not like the other. Kentucky is one of the reddest states in the country - at least at the national level. And yet it has a Democratic Governor, Steve Beshear who invested a great deal of political capital in making Obamacare work.
Kentucky fully bought into Medicaid expansion and built one of the best exchange websites in the country. (Here's a good article at what went into that latter success.) Given the politicization of 'Obamacare' they were also strategic about branding the effort under its state name, Kynect.
Kentucky's success is a testament to what is possible when key elected officials are genuinely invested in the wellbeing of their citizens, particularly those at the lower end of the income spectrum. Kentucky is one of the least healthy states in the country and it's a fairly poor state. "For us to make a transformational difference, we needed to do something game-changing." Beshear told TPM in an interview last year. "The (Affordable Care Act) provided us a tool to do that. It's succeeded so far beyond our wildest dreams."
On other data point. The top five is pretty similar if you look at just private insurance enrollments: Vermont, Rhode Island, Connecticut and Washington state are each on that list. But California is too, at number three. Kentucky has a respectable 11%. California is at 15%.
I'm not totally sure why that is in California's case. They have a very good exchange website by national standards and I believe they were fairly aggressive in pushing people out of substandard plans. So those are both likely factors.
One final point, which mixes politics and policy in a darkly ironic fashion. When enrollment numbers are low, the problem isn't principally the total number as what that number suggests about demographic breakdown. The people most likely to seek out coverage are those who need it badly. So if relatively few people sign up you're likely to have a high percentage of sick people. The numbers tend to be the lowest in the redder states. Most of those chose not to set up exchanges and many actively sought to impede private sector groups (often with federal funding) working to help people navigate the enrollment process.
In other words, the chances of market failure (or so-called insurance market 'death spiral') is probably highest in the states whose political leadership is most desperate for Obamacare to fail.