As consumers rushed to sign up for insurance on the last day of open enrollment under the Affordable Care Act, Maryland's health exchange website slowed to a crawl and all circuits were busy at the call center.

That worsened a bottleneck of consumers who have tried for months to overcome glitches on the troubled website to be able to buy a private plan or sign up for Medicaid. Consumers had faced a fine for not meeting the Monday deadline to get health coverage, but thousands will still be able to sign up.

Maryland officials decided not to penalize those who at least started the process to enroll through the exchange but were stymied by glitches, and will allow them to enroll for several more weeks.

But some consumers couldn't even log on or reach anyone at the call center. They will be allowed to attest that they tried to enroll but couldn't by checking an online box, which officials plan to add to the exchange website, marylandhealthconnection.gov, on Tuesday.

"It's been a whirlwind day," Carolyn Quattrocki, interim exchange director, said Monday evening. "We're going to have a lot of people get through, and that's good news. We'll get many more through in the next month."

Exchange officials said heavy volume — not technical problems — burdened the system Monday.

The exchange enrolled a record 1,700 on Friday and has surpassed that number each day since, Quattrocki said, though exact figures for more recent days weren't available.

The website has been so glitch-prone that up to 11,000 applications were in limbo at one time. Exchange officials have sent out email blasts to thousands of people stuck in the system to offer help with enrolling, and have kept a list of those who had logged on and started the process but were unable to complete it.

Officials are expected to ditch the software and develop a whole new system before the next open enrollment in November. The board that oversees the system plans to vote Tuesday on a proposal to adopt the platform developed by Deloitte Consulting LLC and used in Connecticut.

In the meantime, so-called navigators, those who have been tapped to help consumers enroll in health care, say they expect to continue to be busy for weeks.

"The next big step is after today we'll start making all of these appointments for the people who have touched us that we couldn't help," said Sheila Mackertich, vice president of health reform initiatives at HeathCare Access Maryland, a navigator group.

The group said it was slammed Monday with hundreds of people, some of whom were waiting outside the downtown Baltimore office when it opened. Some said they had waited for the website to improve before trying to enroll, while others said they were rushing to meet the deadline, Mackertich said.

Each of the group's navigators can only handle six or seven applications a day. Many of those who showed up Monday will be added to the list to be enrolled later.

HeathCare Access Maryland encountered a similar line of people at an enrollment fair it hosted on Saturday, where more than 500 people sought coverage. Israel Labasttida, a restaurant worker in Prince George's County, and his wife, Annamaria, were among the last to be signed up for coverage on Saturday.

"She tried the website, and it kept breaking down," said Labasttida, who has largely been without insurance since moving from Mexico 20 years ago. "We looked for a fair and ended up driving all the way to Baltimore before the deadline. It took half a day."

Exchange officials couldn't say Monday when they expect to complete enrollment for everyone who couldn't get through the process, or how many will be left without coverage.

About 400,000 were uninsured in Maryland and qualified for coverage under the federal health law at the start of open enrollment Oct. 1.

As of March 22, nearly 270,000 people had obtained new insurance through public or private plans, though exchange officials can't say how many already had coverage. The bulk signed up for Medicaid, the federal-state program for the poor, which has no enrollment deadline.

Almost 49,300 people signed up for private insurance through the exchange, falling below a target of at least 75,000 set by analysts for the state. While that target was revised from about 150,000, state officials now say the overall number of people with new public or private policies is on track with their expectations.

An unknown number of people also have signed up for coverage directly though four private insurance companies. Consumers were allowed this option when problems with the exchange mounted.