President Trump says the revised House GOP health care bill would protect people with pre-existing conditions, but a multitude of experts and advocates beg to differ.

The latest change to the bill, called the MacArthur amendment after its author, Republican House member Tom MacArthur, would allow states to opt out of several key Obamacare insurance regulations. Two of these are critical for protecting those with health care issues obtain policies that are affordable and cover their treatments.

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Obamacare revolutionized health insurance for people with pre-existing conditions who buy policies on the individual market. Prior to the health reform law, consumers with a medical issue -- even if it were years earlier and completely resolved -- could be denied coverage or charged much more in premiums.

The MacArthur amendment keeps Obamacare's guaranteed access clause, which requires insurers to provide policies to those with pre-existing conditions. MacArthur and other politicians cite this part of the bill to say that the sick and formerly sick would continue to be protected.

But the bill would allow states to apply for waivers that could greatly change the cost and quality of their coverage.

States could opt out of the law's essential health benefits measure, which requires insurers to cover 10 main benefits, including hospitalization, prescription drugs and other services.

Insurers in those states would likely offer skimpier policies that don't cover all the treatments and medications that those with medical issues need. Carriers would be hesitant to offer more comprehensive policies because they would attract consumers with costly conditions.

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The amendment would also allow states to change Obamacare's community rating provision, which bans insurers from charging enrollees more based on their medical history. Under the revised bill, insurers could charge higher premiums to those with pre-existing conditions who let their coverage lapse.

States that apply for this waiver would have to set up high-risk pools or other programs aimed at minimizing insurers' exposure to costly policyholders. This could offset some of the price hikes carriers would levy on those with pre-existing conditions.

But experts say the $130 billion that Republicans would set aside to fund these programs through 2026 is woefully inadequate. High risk pools existed before Obamacare, but most were underfunded, charged policyholders high premiums and had waiting lists.

Health policy experts, consumer advocates, provider groups and even some Republican lawmakers have voiced concerns about how the amendment would affect those with medical issues. Several have come out strongly opposing the revised bill.

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"The individuals and families we represent cannot go back to a time when people with pre-existing conditions could be denied coverage or forced to choose between purchasing basic necessities and affording their health care coverage," said a coalition of 10 patient advocacy groups, including the American Diabetes Association, the American Cancer Society and the National MS Society.

Also, many lower-income people could get caught by this amendment if the bill becomes law, noted Sabrina Corlette, research professor at Georgetown University's Health Policy Institute. A Congressional Budget Office analysis of an earlier version of the bill found 24 million more people would be uninsured under the GOP legislation, and experts say that number could grow as a result of the recent changes.

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These uninsured folks could encounter higher premiums when they try to return because insurers would be allowed to set rates based on their health backgrounds.

"If they try to go back in, they will face insurers that could price them out of the market if they have a pre-existing condition," she said.