New requirements under national health care reform have left health administrators struggling to navigate changes in the state health insurance program and some Islanders scrambling for coverage.

The Martha’s Vineyard Hospital will stop accepting insurance through Network Health as of March 31, a communications director for Partners Healthcare confirmed this week, and policy holders must apply for new coverage using the Massachusetts Health Connector by that date. The hospital is still accepting MassHealth under new managed care plans.

MassHealth is a public health insurance program that combines Medicaid and the Children’s Health Insurance Program, both federal programs, into one program. Network Health is a nonprofit company that contracts with the state to provide comprehensive health coverage through Commonwealth Care, a program for low and moderate-income Massachusetts residents who have no health insurance. Both programs came about following the state’s mandatory health insurance program which was adopted in 2006.

Network Health has held a contract with Partners Healthcare since 2007 and when the Island hospital was acquired by Partners in 2008, it became part of that contract.

Rich Copp, vice president of communications for Partners, the parent company for the Vineyard hospital, said on Monday that the exit of Network Health from Partners is an example of the changes happening in many hospitals following passage of the Affordable Care Act.

“It’s a common thing in these exchanges, a lot of insurers are creating these narrow networks,” he said. “Blue Cross/Blue Shield, for example, up in New Hampshire, excluded a quarter of the hospitals up there. In this new exchange, Network Health . . . does not include Partners in their narrow network.”

In 2011 Network Health narrowed its coverage to exclude Partners hospitals but made an exception for the Vineyard. Last fall that changed and Network Health was due to end its coverage on the Vineyard as of Dec. 31. Later an extension was granted until March 31.

Sonya Hagopian, vice president of corporate communications and public relations for Tufts Health Plan, which owns Network Health, said in a statement to the Gazette that the insurance group and the hospital were not able to reach an agreement on the payment reimbursement level.

“Despite a serious and sincere effort on both sides, we were unable in our discussions with Partners to find a payment level that each of us felt we could live with in order to continue with Partners as a part of our network,” she wrote. “We have a strong network that meets the needs of our members in most of the state, but unfortunately not on [Martha’s Vineyard and Nantucket] where Partners is the sole hospital provider.”

She said Network Health has signed a transitional agreement with Partners to continue to provide coverage for members on the Island during the transition.

This transition has been complicated, or, in the words of Ed Olivier, chief financial officer for Martha’s Vineyard Hospital, “this is a mess.”

The hospital now holds contracts with two new commercial managed care companies, Boston Medical Center HealthNet Plan and Neighborhood Health.

Mr. Olivier said that about 400 individuals were auto-enrolled in BMC HealthNet by the state, but then mistakenly assigned to off-Island providers. An additional 400 individuals whose plans did not change were inadvertently reassigned to off-Island primary care physicians, either in Falmouth or elsewhere on Cape Cod. The computer did not realize these patients were already under the care of Island doctors and when it tried to add them again, the case load came up full and the patients were turned away from their own doctors.

“The reason why we were full is because those were already our patients,” Mr. Olivier said. “It’s an error, it shouldn’t have happened, but it did,” he said.

The hospital has signed one-year contracts with Neighborhood Health and BMC HealthNet, with the expectation that those contracts will continue into the future, Mr. Olivier said.

“They are set up to renew every year automatically, but every health plan will reassess how they’re doing in our area and decide if they want to continue to contract,” he said.

Mr. Olivier said the hospital is working to educate the front desk staff at the hospital and doctors’ offices to work with patients through the confusion.

“The more important thing for patients is for them to have long term access to health care and that means getting them on plans that we are contracted with longer than March 31,” Mr. Olivier said.

“I personally went around and met with the leadership of all of our patient facing departments . . . about what we need to do in order to be helping our patients get connected long term with plans that are going to give them access to health care,” he said. Those departments included physicians’ offices, central registration, rehabilitation, the lab and financial counselors.

And yet for the individual, the recurring changes continue to be daunting.

For example, Kathy, who asked that her last name not be used, has had three different insurance plans since August. She has hepatitis D and has been traveling between Boston and the Vineyard for treatment.

“It’s all automated and you hardly get a hold of a person and when you finally do, you don’t know what you’re exactly supposed to do,” she said. “I kept getting switched form one place to another . . . it’s been crazy.”

Vineyard Health Care Access, the program that helps people navigate health insurance issues, helped Kathy enroll in the BMC Plan, which was needed for treatment at the Falmouth Hospital. But when she got to Beth Israel Hospital in Boston to secure a needed prescription, the hospital would not accept her insurance. Within 24 hours she had to change to the Neighborhood Health plan in order to receive the medicine she needed.

“Since then they’ve had a problem with who’s going to pay for the medication, so I’m still with the Neighborhood Health plan but they wouldn’t fill the prescription on-Island,” she said. She is still waiting for her medicine to arrive in the mail.

“People are generally frustrated, confused and concerned,” said Sarah Kuh, director of Vineyard Health Care Access. “It’s a big change.”

Ms. Kuh confirmed that there has been considerable confusion on the Island about the changing programs. Other health insurance plans are also ending, including a subsidized insurance plan for fishermen called the Fishing Partnership

“Some people are in limbo as a result of this situation [but] most people still have their insurance or are newly insured,” she said. “Because of the problems with the [federal] website not working, the state did come up with temporary coverage for people who are applying but haven’t been approved yet. They should be covered by MassHealth.”

Ms. Kuh urged people not to wait until the March 31 deadline to make arrangements.

“It takes a long time to process the applications,” she said. “To be on the safe side, I’d love to see everyone who needs to reapply [to complete applications] by the end of January.”

After the March 31 deadline, the next enrollment period will run from October through December for coverage starting Jan. 1, 2015. Open enrollment began on Oct. 1.

People can apply online, over the telephone or fill out paper applications which are available at the Vineyard Health Care Access office or can be found online and printed out.

“They can fill them out and we’ll review and process them,” Ms. Kuh said. “People should persevere. They need to call as many times as they need to get through to somebody who can verify the status of their application and confirm that it’s been received. If they haven’t received a response in a timely matter, within six weeks, they need to follow up.”

To apply for health insurance over the phone, the number is 1-877-623-6765. To obtain an application in person, visit the Vineyard Health Care Access office at 114 New York avenue in Oak Bluffs or visit mass.gov/eohhs/docs/masshealth.