(CNN) -- When Jody Sabatino opened her mailbox last month, she got some jaw-dropping news: Her insurance company, UnitedHealthcare, was cutting the 79-year-old's most trusted doctor from its Medicare Advantage plan. In fact, four of her six regular doctors won't be covered at all next year.
"I couldn't believe it. I just couldn't believe it," Sabatino said.
What's easier to believe for those affected by the cuts is that because Obamacare makes it harder for insurers to cut patients from their rolls, they're cutting doctors instead -- and hoping patients follow them off the plan.
United's move left Sabatino and her 94-year-old husband, Nick, facing a tough choice: Do they stay with United and find new doctors or try to keep their doctors by finding a new insurance plan?
"Dr. Mieczkowski has been my doctor for 20 years. No one knows me any better than he does, and it's silly not to continue to go with him," Sabatino said.
So she went shopping. And the insurance plan she bought is going to cost her more. Of the eight prescriptions that United covered, half of them are either going to cost more or aren't covered at all under her new plan.
But by switching plans, Jody Sabatino gets to keep Dr. Lawrence Mieczkowski, or "Dr. Mitch." The cardiometabolic specialist will be unceremoniously dumped from United's Medicare Advantage network next year with little explanation.
"Given the significant changes and pressures in the health care environment, we have undertaken a review of our network and are making changes to its composition," United wrote to Mieczkowski in an August letter. "As a result, UnitedHealthcare is amending your agreement referenced above to discontinue your participation in the Medicare Advantage network effective on January 1, 2014. ... This amendment does not require your signature."
But the doctor thinks United is trimming physicians from its networks in hopes that their patients will follow.
"Let those high-cost patients move out of the UnitedHealthcare Medicare Advantage plan over to Anthem or Humana and let those poor suckers, so to speak, pick up the cost," Mieczkowski said.
In Ohio, where Mieczkowski practices outside Dayton, hundreds of doctors and thousands of patients have been affected by United's cuts. And in Connecticut, United cut about 20% of its doctors, according to the state medical society. The American Medical Association says United and other insurers have taken similar action in at least a dozen states.
"The patient costs a lot," said Todd Baker of the Ohio State Medical Association. "And United is going to those patients' doctors and dropping them and therefore getting rid of the patient."
United concedes it is reducing the size of its Medicare Advantage network, saying it will shrink by about 10% to 15% by the end of next year.
"Many health plans are making changes to their networks to improve quality and keep health insurance affordable," United said in a statement to CNN. "These changes are necessary to meet rising quality standards in an era of Medicare funding cuts, and will improve our ability to work closely with physicians and encourage better health outcomes for our members."
The insurance industry's trade group argues that the changes are a direct result of Obamacare. To help pay for health care reform, lawmakers included $200 billion in cuts to the Medicare Advantage program and a new tax on health insurers.
"Washington can't cut and tax the Medicare Advantage program this much and not expect seniors in the program to be harmed. And that's exactly what we're starting to see," said Robert Zirkelbach of America's Health Insurance Plans. "This is just the beginning. As more and more of these cuts go into effect over the next several years, seniors are going to face even higher premiums, higher out-of-pocket costs for services and fewer health care choices."
And even though Sabatino was able to find a plan that allows her to continue to see Mieczkowski, she will still lose two other specialists.
"We're walking away from people that we've known and trusted and counted on for over 10 years, and that's hard," she said. "That's hard."