The supposed implosion of the Affordable Care Act s private insurance markets looks more and more like a manageable, geographically limited problem one that policymakers could fix pretty easily, if only some of them werent trying so hard to undermine the program.

The latest development comes out of Nevada , where until last week 14 counties had no options lined up for the states insurance exchange in 2018. Centene , which already offers policies in parts of Nevada, announced on Tuesday that it would expand next year to offer policies statewide which means roughly 8,000 exchange customers in those 14 counties will have a way to buy the Affordable Care Acts regulated, subsidized policies.

Those thousands of people would have been stuck looking for some other source of insurance had their counties remained bare, with no carriers on the exchange. And because people buying policies through the exchanges dont typically have access to employer-sponsored plans or qualify for government programs, most of those people would have ended up with no coverage at all.

The problem of bare counties has gotten a lot of attention in the last few months. Many insurers have scaled back their presence in the new Obamacare markets, citing their inability to make a profit because they cant attract a stable mix of healthy and sick customers. Republicans have repeatedly said this exodus is a sign of the programs collapse, and a reason to repeal the health care law.

House Speaker Paul Ryan (R-Wis.) once called repeal an act of mercy because, he said, the programs new markets would fall apart without intervention.

But even as most of the big, commercial carriers like Aetna and Cigna have beat a hasty retreat from Obamacare, carriers like Centene have filled in the gaps . At this point, only two counties nationwide have no carriers lined up for next year. One is in Ohio, the other in Wisconsin. Together they account for roughly 400 customers, and its not too late for those counties to get insurers, too.

That doesnt mean everything is hunky-dory. Centenes business model relies on narrow physician networks to keep premiums down, which isnt what all consumers would prefer. And although the number of truly bare counties has now shrunk to nearly zero, there are still many that only have one insurer. Roughly 40 percent of all counties will have just one exchange insurer in 2018, according to the latest figures from the Department of Health and Human Services.

But even that number is a little misleading, because those counties are disproportionately rural. In other words, not that many people live in them.

This isnt surprising. Rural counties are inherently difficult for insurers to manage, because the low numbers of customers make it difficult to get that ideal mix of healthy and sick enrollees and because the relative paucity of doctors, hospitals and clinics makes it impossible for insurers to play providers off of one another to get lower prices. This was true before the Affordable Care Act was passed.

To put all of this in perspective to show just how many people will really feel the effects of dwindling insurance options, and which parts of the country they call home Harold Pollack , a social scientist at the University of Chicago, and Todd Schuble, a computational scientist there, drew up two maps. They originally posted them at healthinsurance.org and have since adapted them for HuffPost.

One map shows counties with standard geographic borders. The area covered by counties with just one insurer is substantial.