Just two weeks before open enrollment, UnitedHealth Group’s decision to drop doctors from its Medicare Advantage network has doctors and patients upset and confused.

Last week, physicians received letters from UnitedHealth informing them that they had been “terminated without cause,” effective February 1, 2014, according to the Fairfield County Medical Association and Connecticut State Medical Society. But it’s still unclear exactly how many doctors were affected by the decision.

A UnitedHealthcare spokesman declined to answer questions about how many doctors may be impacted by the decision.

“We offer our members one of the most extensive networks of health care providers in Connecticut and remain committed to ensuring they have continued access to quality, affordable care,” Ben Goldstein, a UnitedHealth spokesman for the region, said Thursday in an email. “Members with questions are encouraged to call the customer service number on the back of their member ID card for more information.”

Mark Thompson, executive director of the Fairfield County Medical Association, said Friday that patients are calling the insurance carrier, but the answer they get depends on what time of day they call. He said he’s spoken to patients who called in the morning and were told their doctor was on the plan, but when they called back in the afternoon the doctor was off the plan.

“There’s mass confusion,” Thompson said. “Even the company doesn’t know what’s happening.”

A patient who has six months to live called yesterday in tears because she was told she will have to find a new oncology doctor, Thompson said, adding, “Can you imagine?”

He said UnitedHealth needs to stop this and rescind the letters until it knows what’s happening.

The doctors who received the letters serve some of the sickest patients, many of whom suffer from four or more chronic conditions. One of the largest dialysis groups in Bridgeport received notification that they will no longer be able to accept UnitedHealth’s Medicaid Advantage, which will force patients to go to New Haven or Long Island, New York. Thompson said the equation used to calculate the nearest facility apparently doesn’t take into account a body of water called the Long Island Sound.

For the average patient, driving an extra five miles for care can be an inconvenience, representatives of the Connecticut State Medical Society said Thursday in a release. For seniors with limited mobility, those same five miles can be a significant barrier to access.

“The timing is questionable,” CSMS President Dr. Michael F. Saffir, said. “This comes less than two weeks before Medicare’s Open Enrollment period — how can seniors make informed decisions when their own doctors don’t even know whether they’re in the United network?”

Open enrollment for the programs begins Oct. 15 and runs through Dec. 7.

Thompson said he understands that UnitedHealth is doing this to manipulate their “profitability by controlling their network,” in order to raise its rating under a new five-star system established under the Affordable Care Act. But “it’s a step in the wrong direction,” he added.

The Fairfield County Medical Association and the Connecticut State Medical Society said UnitedHealth has refused to tell them which doctors received notices and even some of the doctors who did receive notice may still be in the UnitedHealth Medicare Advantage network. They also refused to tell the organizations what criteria they used in kicking doctors out of the network.

Both organizations have been in touch with federal officials, Medicare advocates, and lawmakers since the news broke last week.

Medicare Advantage plans cover Medicare Parts A and B. They are funded by the federal government, but administered by private insurance companies who attract customers by offering other cost protections not available under traditional Medicare.

Thompson said that because these insurance carriers are administering a public program, there’s a “moral” responsibility that they have to be good corporate citizens.

“They are stewards of a public health care program,” Thompson said.