NEW YORK — NEW YORK — The much-anticipated debut of the enrollment period for health insurance exchanges saw millions of Americans overwhelm the websites set up to let them get coverage.

Proponents of the Affordable Care Act (ACA) health reform law say the sheer number of people who turned to the sites on the first day they could enroll is evidence of a broad national appetite for the affordable health insurance coverage that President Obama has promised with his health care overhaul.

Much of that enthusiasm, however, was dampened as potential enrollees encountered technological problems that prevented them from getting rates, comparing health plans or signing up.

Federal and state officials said that while they knew there was pent-up demand for health coverage, the number of visits to their exchanges was greater than anticipated.

Officials report that during the first day and a half of the enrollment period HealthCare.gov, the federally run exchange that serves residents of 34 states, received more than 6.1 million unique visitors. In addition, nearly 200,000 people called the federal call center set up to help consumers navigate the exchanges.

State-run exchanges also reported higher-than-expected use, with some states saying their sites had several million visits on the first day.

For instance, officials in New York state, which is running its own insurance site, said there were more than 30 million website visits in the first 48 hours after it debuted.

Meanwhile, some states were forced to shut down their exchange websites for several hours, while others delayed fully launching their state ­marketplaces.

People looking to get health insurance through the exchanges have until December 15 to enroll for coverage that will go into effect on January 1, the date specified under the ACA’s mandate that all Americans have health coverage or pay a penalty.

However, the open enrollment period for 2014 marketplace coverage runs through March.
Officials say they expect that about 7 million people will eventually buy coverage through the health insurance exchanges this year with the bulk of these people being those who are currently uninsured or who usually buy their own policies on the individual market.

By 2016, they note, the ranks of the newly insured are expected to swell to more than 20 million.

Administration officials say the greater-than-anticipated number of people who went online looking to buy health insurance underscores the need to provide affordable coverage to the nearly 50 million uninsured consumers who either couldn’t afford coverage or were excluded from plans because of existing medical conditions — one of the major issues the reform legislation sought to address.

“That gives you a sense of how important this is to millions of Americans around the country,” Obama said on the day the exchanges opened for business.

The problems that plagued the first day of enrollment, he said, were expected to be quickly rectified, allowing the government to accommodate the larger-than-expected demand.

Critics of the ACA say the troubles consumers had on the first day of enrollment show that the program is being rushed into effect.

“This law was never ready for prime time and never will be,” Rep. Renee Ellmers (R., N.C.) said in a statement published on her website on the day the exchanges went live.

The problems with the debut of the insurance exchanges, Ellmers noted, were part of the objections she and other Republican members of Congress have with the health care reform law.

“We discovered that health insurance rates are expected to triple for women and quadruple for men in North Carolina once this law goes into effect,” Ellmers said. “We were promised lower costs and more competition. The whole point of an online marketplace was to provide options, but as we are seeing, this couldn’t be further from the truth.”