The state of North Carolina is blaming locally based software provider Benefitfocus for long phone delays some of its workers and retirees have faced when trying to sign up for their medical coverage.

Administrators of the state health insurance program said the problem began when the enrollment period opened on Oct. 1, according to a report in The News & Observer.

The N.C. Department of State Treasurer officials said there have been long delays when members have called in for help, with some waiting more than an hour.

The enrollment period was recently extended to Nov. 15 from Oct. 31 because more than half of the 664,000 North Carolina state workers and retirees in the system had not yet picked an insurance plan, according to the publication.

Daniel Island-based Benefitfocus has been managing the enrollment of the state program since 2009, officials said.

Last year, North Carolina hired it to handle the benefit eligibility and enrollment services for employees, teachers, retirees and their dependents covered by the State Health Plan.

The company also is responsible for providing assistance when members call in for help.

“Members calling our Eligibility and Enrollment Support Center, which is Benefitfocus.com, have experienced long hold times while trying to gain assistance with their enrollment,” said Schorr Johnson, a spokesman for Treasurer Janet Cowell, whose office hired the company. “We have been pushing Benefitfocus to add additional support staff in an effort to reduce these wait times and improve the customer experience for our members.”

In a written statement Thursday, Benefitfocus spokeswoman Nina Sossamon-Pogue would not address questions about the phone delays. She stressed that the online enrollment option has “maintained 100% system availability and response times of less than one second.”

Andy Howell, chief operating officer, told The News & Observer this week that the company has added 75 workers to handle the call volume and would hire more if necessary.

Benefitfocus is one of the largest online workplace benefits providers in the nation.

More than 18 million individuals, 300,000 employers and 60,000 brokers use its cloud-based platform to shop for, enroll in and manage their benefits in one place.

The company raised $70.6 million in September to fund its growth plans by selling stock to the public.