It’s begun: doctors turning away patients covered under the Affordable Care Act because the physicians aren’t being reimbursed at a rate that allows them to “keep the lights on.”

It’s a twofold problem, because doctors need patients in order to stay in business, and patients need doctors because, well, they’re either sick or trying to manage their health to reduce their chances of getting sicker.

But more and more doctors are beginning to decline patients covered under Obamacare plans because the reimbursement rates are too low to make accepting their insurance an economically viable option. Meanwhile, many patients under ACA plans are funneled into coverage networks that offer limited healthcare choices in order for insurers on the network to keep their costs manageable.

NPR recently interviewed Connecticut doctor Doug Gerard for a story on Obamacare — from a physician’s point of view. Gerard said it makes no sense to admit Obamacare patients whose coverage pays out at a rate that’s roughly 80 percent of what he receives from private insurers that cover patients who aren’t participating in an Obamacare exchange.

On a recent afternoon at his office in Hartford, Conn., Dr. Doug Gerard examines a patient complaining of joint pain. Gerard, an internist, checks her out, asks her a few questions about her symptoms and then orders a few tests before sending her on her way. For a typical quick visit like this, Gerard could get reimbursed $100 or more from a private insurer. For the same visit, Medicare pays less — about $80. And now, with the new private plans under the Affordable Care Act, Gerard says he would get something in between, but closer to the lower Medicare rates. That’s not something he’s willing to accept. “I cannot accept a plan [in which] potentially commercial-type reimbursement rates were now going to be reimbursed at Medicare rates,” Gerard says. “You have to maintain a certain mix in private practice between the low reimbursers and the high reimbursers to be able to keep the lights on.” Three insurers offered plans on Connecticut’s ACA marketplace in 2014, and Gerard is only accepting one. He won’t say which, but he will say it pays the highest rate to doctors. “I don’t think most physicians know what they’re being reimbursed. Only when they start seeing some of those rates come through will they realize how low the rates are they agreed to.”

Smaller private practices have much more difficulty maintaining that “certain mix” of patients at different coverage levels in order to run a business that’s both ethical and profitable. But even hospitals, which have historically accepted more types of coverage from broad patient demographics, are beginning to struggle with the small returns on Obamacare plans.

“[H]ospitals — especially top-tier ones that treat the most difficult diseases — are also increasingly rejecting the low reimbursement rates,” The Daily Caller observed Monday. “The nation’s best cancer treatment centers are often covered by very few exchange plans in their states; if Obamacare customers end up with a difficult-to-treat cancer, they’re likely to face a lower quality of care right off the bat.”

Over time, this trend could lead to a form of quality-of-care segregation in which certain types of health care providers who accept Obamacare patients dole out faster, cheaper and poorer services than providers who limit their acceptance of Obamacare-backed plans.

“If reimbursement rates to doctors stay low in Obamacare plans, more doctors could reject those plans. And that could mean that people will get access to insurance, but they may not get access to a lot of doctors,” NPR reported.

“I think it could lead potentially to this kind of distinction that there are these different tiers of quality of care,” Kevin Counihan, manager of Connecticut’s AccessHealthCT insurance exchange, told the network.