MONTPELIER, Vt. — Improvements continue to be made to Vermont’s health care exchange system, which had been plagued with problems, Gov. Peter Shumlin said Thursday.

While announcing the improvements and open enrollment period which runs from November 1 through January 31, Shumlin said more progress needs to be made to Vermont Health Connect.

“My biggest frustration right now is that wait times are too long when you call the call centers,” he said. He said he met last week with the president of the company that is providing the service, which he said has promised to bring on more staff to reduce the wait times.

Among the improvements Shumlin cited:

— nearly nine out of 10 Vermonters who ask for a change of circumstance to their coverage — such as for the birth of a child or a marriage — experience a smooth process;

— the backlog of those requests has been reduced from 10,000 last spring to 1,200;

— 85 percent of Vermonters’ requests are being processed in 10 days;

— the error rate on transactions has dropped from 3.5 percent in May to 2 percent in September; and

— staff are able to resolve urgent and complicated cases more quickly. The number of escalated cases that cause Vermonters longer delays has declined from more than 250 this spring to 19.

“When I continually read that Vermont Health Connect is mired in problems and challenges, I want to make clear that that was true but it’s not anymore,” Shumlin said.

When the system’s website first went live in 2013, it was unable to process change of circumstance requests and failed to properly verify Social Security numbers, family income or the incarceration status of the applicant, according to a federal audit.

Republican gubernatorial candidate Phil Scott has called for the state to do away with the exchange and join the federal exchange or a multi-state option.