Maryland’s health exchange Web site is still riddled with glitches and might need to be completely overhauled — or even abandoned — once the first round of enrollment ends March 31, a member of Gov. Martin O’Malley’s Cabinet told lawmakers Tuesday.

Until then, state officials say they have come up with a system of temporary fixes aimed at getting as many Marylanders as possible signed up for health coverage before the deadline. That has included hiring dozens of people to staff call centers and, in some cases, resorting to paper applications.

“There are serious challenges that still remain. I don’t want to sugar­coat that,” Joshua M. Sharfstein, secretary of health and mental hygiene, told members of the state Senate Finance Committee late Tuesday afternoon. “It’s going to have to improve for us to stick with it for the long term.”

His comments came as legislators are looking into how the state’s rollout of its health exchange, part of President Obama’s Affordable Care Act, went so wrong. State officials were among the earliest and most enthusiastic supporters of the federal health-care law, and Maryland was one of 14 states that chose to run its own health insurance marketplace. But the online site crashed when it was launched Oct. 1 and has been plagued by technical problems that have stymied an unknown number of Marylanders from signing up for coverage.

The General Assembly is expected to vote as early as this week on emergency legislation to assist those who tried unsuccessfully to sign up and were left uncovered when the new year began. The bill would provide retroactive coverage through a separate state-run insurance plan that normally covers high-risk individuals.

Also, O’Malley (D) announced Tuesday that the four insurance carriers participating in the state’s exchange have agreed to provide coverage that is retroactive to Jan. 1 as long as residents sign up by Jan. 21 and pay their premiums for January and February.

Sharfstein began his remarks before two separate panels of legislators by acknowledging the troubled launch of Maryland’s exchange and apologizing to the people without insurance who have been impacted.

“I take responsibility for the disappointing launch,” he said in his opening remarks. “I apologize to the many Marylanders who have struggled with the Web site and the call center, and I regret the anxiety experienced by individuals and families who are seeking health insurance and have been frustrated in their efforts to obtain it.”

O’Malley and Lt. Gov. Anthony G. Brown (D) announced Tuesday that they will stick with the state exchange for the remainder of this enrollment period, which ends March 31, and that they have no plans to begin using all or part of the federal exchange. Switching at this point would only complicate the situation, they said.

But beginning April 1, the site will have to be reassessed and all options will again be open, Sharfstein said. If by then the federal exchange or another state’s exchange was stronger than Maryland’s, he said, officials would consider using all or parts of those.

Brown, who was in charge of implementing the Affordable Care Act in Maryland, came before the panels earlier in the day, but he did not face as intense questioning as Sharfstein. After a Republican senator asked him to apologize, Brown said Marylanders would rather see action than an apology.

Brown, a candidate for governor, has said that his job was to set up a legislative framework for the exchange — and that the exchange’s governing board, staff and the contractors hired to create the Web site failed to let him know that it would not be ready for its Oct. 1 launch.

“Never was I informed that the exchange, the Web site, would not be able to — or would be unable to — launch on October 1st,” Brown said at the Senate Finance Committee hearing when asked whether he had seen reports that contained warnings of problems. Brown said that he was told there could be problems for families with unique or complicated circumstances, but “that was the extent of it.”

One of the most intense lines of questioning came from Senate Minority Leader David R. Brinkley (R-Frederick), who compared the “colossal failure” of the health exchange to a botched military operation. Brinkley said to Brown, a colonel in the Army Reserve, that just as the military has forms of accountability, so should Maryland.

“With all of the resources and sophistication that Maryland has, we’ve been embarrassed by this,” Brinkley said. “We need to get to the root of this because it put a black eye on everybody.”

Lawmakers criticized state officials for not keeping them in the loop on problems, both before the launch of the site and afterward. They said Sharfstein and other officials should have shared monthly audit reports that contained red-flag warnings. And some said that their faith in the state’s health-care leadership was so shaken that they weren’t sure it can be trusted with further projects.

In questioning Sharfstein, some lawmakers compared building a health exchange Web site to hiring contractors to renovate a kitchen or build a deck. One delegate compared it to sixth-graders making science fair projects with varying success.

Sharfstein gave legislators a thick packet of documents that included his answers to questions such as “Why did the Maryland Health Benefit Exchange procure this system from these vendors?” and “How did the state respond to early warning signs?”

He said that at the heart of the dysfunctional Web site are three significant problems: Maryland opted to use “off-the-shelf” software and did not realize how much work it would take to stitch the different programs together; there were “serious software defects”; and the hardware was poorly configured, resulting in the crash of the site on its Oct. 1 launch.