One of the nation’s biggest health insurers says it will not return to Ohio’s public insurance exchanges next year, a decision that could open more holes in the Affordable Care Act’s increasingly thin system for helping people buy coverage.

The move announced Tuesday by Anthem could leave shoppers in 20 counties without an option for buying individual coverage on the exchange unless another insurer steps in.

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According to Robert Wood Johnson Foundation data that looks at state markets where all insurers must sell plans that meet Obamacare standards, regardless of how they’re purchased, more than half of the 22 million people who buy their own insurance use Obamacare marketplaces, where most of them get a federal tax credit to help pay for coverage. The rest buy directly from an insurer or broker, and they do not get a tax credit. Supporters of the Affordable Care Act hoped the law would spur more competition among insurers across the country. But so far, the law has not delivered on that promise, especially in states that never had much competition. Even before Obamacare, there have always been two distinct markets: states that still have plenty of competition and states that rely heavily on one or two insurers. In 15 states, eight or more insurers offer Obamacare plans. They are mostly the same ones where no single insurer had a dominant share of the market in 2013, before the law was enacted. But the 19 states that currently have fewer than five carriers statewide are all ones where a single insurer had more than half of the overall market before Obamacare.

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Americans view Humana Inc. and Aetna Inc. no less favorably after the industry giants announced their plans to pull out of the Affordable Care Act’s individual exchanges in 2018, according to Morning Consult Brand Intelligence data.

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Blue Cross and Blue Shield of Kansas City announced yesterday it has decided to exit the Obamacare exchange next year. The decision affects about 67,000 Blue KC customers in 30 counties in western Missouri as well as Wyandotte and Johnson counties in Kansas. Danette Wilson, Blue KC’s president and CEO, said that the company has lost more than $100 million total on its exchange plans since the ACA rolled out in 2014.

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A new HHS report reveals that premiums for individual market coverage have increased significantly since Obamacare’s provisions have taken effect. Comparing the average premiums between 2013, before ObamaCare went into effect, and 2017 shows average exchange premiums were 105% higher in the 39 states using Healthcare.gov than average individual market premiums in 2013. Average monthly premiums increased from $224 to $476 over the period, and 62% of those states saw the average premiums double.

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The Trump administration and House of Representatives Monday asked a federal court for another 90-day delay in a lawsuit over Obamacare insurance subsidies. “The parties continue to discuss measures that would obviate the need for judicial determination of this appeal, including potential legislative action,” the House and White House wrote to the court. If the request is approved, the parties would have to file another update in 90 days. “We continue to work with the Trump administration on a solution,” said AshLee Strong, spokeswoman for House Speaker Paul Ryan.

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More than a dozen states and the District of Columbia filed a motion on Thursday to intervene in the appeal of a lawsuit targeting the ACA’s cost-sharing reduction (CSR) subsidies. The lawsuit was originally brought by the U.S. House of Representatives against the Obama administration, which the Trump administration must now deal with. The Kaiser Family Foundation has estimated that the average premiums for silver plans sold on the ACA exchanges would increase by about 19% to compensate for insurers’ lack of funding without the CSR payments. The Trump administration and the House are set to update the court on Monday on how they plan to proceed with the case.

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New York’s health insurers will request double-digit rate increases for ObamaCare policies for 2018 while debate rages in Washington on overhauling the law, analysts told The Post.

The insurers officially submit their rate plans to state regulators on Monday.

Last year, the state Department of Financial Services approved an average 16.6 percent hike for individual policies and an average 8.3 percent for small group policies on the state’s ObamaCare exchange — the highest in four years.

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Of the 498 rating regions in the United States, 146 had only one insurer selling nongroup coverage through its state marketplace in 2017; 125 had just two insurers. Markets with one insurer include the entire states of Alaska, Alabama, North Carolina, Oklahoma, most of Arizona, and rural areas of several states. Markets with only one or two marketplace insurers tend to be much less populated than areas with more competing insurers.

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Health insurance giant Aetna said Wednesday that it will not be participating in any Obamacare exchanges in 2018.

“Our individual commercial products lost nearly $700 million between 2014 and 2016, and are projected to lose more than $200 million in 2017 despite a significant reduction in membership,” T.J. Crawford, Aetna spokesman, said in an email.

The reason for the losses, he said, came from structural issues within the exchanges “that have led to co-op failures and carrier exits, and subsequent risk pool deterioration.”

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