(Reuters) — Stephanie Desaulniers is among the millions of Americans seeking information on the new health insurance plans launched this week — not because she lacks coverage, but because she's ready for a better deal.

The 26-year-old geologist has health benefits through her employer, an environmental consulting firm in Cumberland County, Pa.

"My insurance premiums are going to double next year through my work. Part of it is we are switching companies, but even last year, we were showing substantial increases," she said in an interview. "I was hoping I could find something that was a little cheaper."

President Barack Obama's health care reform law aims to provide coverage to millions of uninsured Americans beginning in 2014. The administration launched new online health insurance exchanges across the country on Tuesday, though technical glitches and heavy traffic meant that many visitors could not log on to research the new plans.

While the White House hasn't made a concerted effort to hold up shoppers like Ms. Desaulniers as beneficiaries of the law, they are expected to represent a significant number of Americans seeking insurance on the exchanges.

The Congressional Budget Office expects as many as 7 million people to enroll in coverage in the first year of the exchanges but has not specified how many already have insurance. The administration estimates 2.9 million uninsured will gain coverage under the law next year.

Over time, as many as 37 million Americans with employer-sponsored insurance may find themselves better off with the government-subsidized plans on the exchanges, according to a recent study in Health Affairs.

Enrollment for the new insurance plans runs through March 31, but for insured Americans making the switch, the deadline will likely come sooner as they must decide whether to go with what their employer offers or not. That makes them more vulnerable to the kinds of technical problems that blocked access to the exchange sites on Tuesday.

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"I was kind of pissed," Ms. Desaulniers said of her stymied effort to log on. "What are the costs of the premiums, and what is the insurance going to cover? That's what I was trying to get on to figure out, to do a cost analysis. I really need time to do that before I have to enroll."

A Reuters survey of readers who said they had tried to access the new Obamacare websites found most were unable to call up data. Out of nine respondents interviewed by Reuters, eight were currently insured.

"I'm pretty excited about the health care exchange because my husband needs insurance and I have my own, so I'm really looking forward to getting low-cost coverage," said Geralyn Pekarske, 59, from Schleswig Township, Wis. The state's exchange is run by the federal government.

She was laid off from her human resources job at a manufacturing company after the 2008 financial crash and has had individual coverage for years. Her husband, a cancer patient, is insured through the state's high-risk pool that will close at year's end with the advent of the exchanges.

Their combined monthly premiums cost over $600, with annual deductibles — or the amount someone has to pay before insurance kicks in — of over $10,000, she said.

"I cringe every time I look at the amount of money that we're spending on health care and insurance premiums," Ms. Pekarske said.