Problems with Maryland’s online insurance exchange, including with paper applications that were supposed to provide a fail-safe backup plan, are so severe that community groups have begun warning uninsured clients that they may not obtain coverage as intended by Jan. 1.

State officials began this week to contact all people whose applications are still pending, urging them to contact the state call center, try the state Web site again or get in touch with a certified insurance broker for help.

At a news conference Thursday, Gov. Martin O’Malley (D) acknowledged the exchange’s “rocky launch” for the second time in recent weeks. But he said the state is on track to meet a goal he set two weeks ago to fix most of the Web site’s technological problems by mid-December. Of nine major issues identified, three remain to be addressed, he said, two of which involve computer screens freezing during the application process.

As of last Saturday, about 5,200 people had enrolled in private plans through the state-run exchange. O’Malley said he remains committed to a goal of signing up 260,000 people by the end of March — 150,000 in private plans and the rest in Medicaid.

Marylanders have until Dec. 23 to sign up for coverage that will start Jan. 1. Insurers have agreed to accept payment up until Jan. 15, 2014, with coverage retroactive to Jan. 1, as long as enrollment was completed by Dec. 23. The Obama administration on Thursday urged the insurance industry to take steps to help consumers obtaining coverage through the federal exchange, including giving them more time to pay. State officials said they were still evaluating what that request might mean for Maryland.

With the Dec. 23 deadline looming, community groups who had relied on paper applications because of problems with the Web site are especially worried about people with critical medical needs.

“Benefits could be delayed,” said Young Eun Lee, who works at the Korean Community Service Center as a “navigator,” or someone who is helping to enroll consumers. She said the center, a D.C. area nonprofit group, has written to 200 to 300 people who submitted applications on paper, advising those who urgently need health services to call the center.

The organization has received a flurry of panicked calls. The callers, she said, include cancer patients and others with chronic conditions. Most of the center’s clients are young adults and small-business owners who are uninsured, center executives said. Many started working on their applications as soon as enrollment opened Oct. 1.

Paper applications had been viewed as a good Plan B, both by the 14 states, including Maryland, that are running their own exchanges and by the federal officials overseeing the site, which serves 36 states. Officials thought that the paper forms would avoid the glitches that have slowed enrollment in the federal marketplace and some of the state exchanges.

But it turned out the paper method does not enable consumers to completely avoid the online insurance marketplaces. In Maryland, workers must enter information from the application into the online system to determine whether an applicant is eligible for Medicaid coverage or for a subsidy to help pay for private coverage. And consumers still have to use the Web site to select a private plan.

Navigators and other workers have run into a constellation of problems using the paper forms. Only certain government buildings, for example, allow Internet access to the “back end” of the online system to allow manual entry. And manual entry is plagued by errors that prevent navigators from finishing the process, leaving applications in limbo.

In two weeks of trying, one navigator said she was able to complete manual entry for just six paper applications out of dozens that she tried.

Jon Kromm, a senior administrator in O’Malley’s health-care reform office, has been assigned by the governor to oversee exchange operations after last week’s resignation of the exchange’s executive director. In an interview this week, Kromm said the exchange recently added 40 people to its call center and 30 to the nine who had been working at a Lanham facility to process paper applications.

Kromm said he had no way to predict how many people the state would attempt to contact to tell them to try again — or how many might be unable to sign up for private insurance by Dec. 23.

Leslie Lyles-Smith, an executive at the Maryland exchange, said 5,565 paper applications have been received, of which 3,496 had been processed. But she did not know how many of those consumers had actually signed up for coverage.

“We’re working as hard as possible,” Kromm said. “Our objective is to do an all-hands-on-deck to get as many people enrolled as quickly as we can.”

Because of the Dec. 23 deadline, the highest priority is to reach people trying to enroll in private plans. Those eligible for Medicaid have until the end of January to sign up for coverage that is retroactive to Jan. 1.

Montgomery and Prince George’s counties account for the largest number of Maryland’s uninsured. Groups helping residents of the two counties have signed up about 400 in private plans and Medicaid, using online or paper applications, said Mary Anderson, a spokeswoman for the Montgomery County Department of Health and Human Services. The department is coordinating enrollment for community groups in both counties.

But at least 3,300 applications, most of which are paper, are pending, she said. To speed up paper processing, community groups spent the week before and after Thanksgiving working at a Rockville office building to enter manually as many paper applications as possible, said navigators and government officials. That effort made only a minor dent in the backlog, they said.

On Monday, community groups turned over responsibility for processing 701 outstanding paper applications to state officials, Anderson said.

“We’re all worried that people won’t get coverage in time,” said Wylea Chase, a navigator with Gaithersburg-based Family Services Inc., which works with immigrant communities.

The organization has enrolled about a dozen people online. But it received about 115 paper applications and turned over to state officials Sunday about 75 for people who would probably have to enroll in private plans. The group began contacting those individuals this week to let them know that “through no fault of their own, they are not currently enrolled,” Chase said.

John Wagner contributed to this report.