"If you are going to insure everyone, you have to make sure that you have doctors to care for those people," Dupee added.
Another struggle for Massachusetts has been its attempts to curb the costs of the law, said Lora Pellegrini, president of the Massachusetts Association of Health Plans. She faulted lawmakers for mandating that insurers cover more procedures and medicine, including hearing aids, oral cancer drugs and an assessment to help pay for the state's childhood vaccine program.
"To ultimately be sustainable, we have to address the costs," she said.
The state has worked to do so. In August, Gov. Deval Patrick signed a bill intended to save Massachusetts up to $200 billion over 15 years by encouraging a system that rewards doctors and hospitals for keeping patients healthy rather than paying piecemeal for every operation or treatment.
Employers must also brace for changes. In Massachusetts, businesses with 11 or more full-time workers were required make a "fair and reasonable" contribution to their workers' health insurance or pay a fee.
At family-owned Needham Electric Supply, five more employees began getting insurance when the law passed, said Vicki Maderia, director of human resources.
The company had considered the workers part-time, but they were deemed full-time under the law. Maderia said the cost was minimal.
"It helped us be a little more marketable because of a lot of the part-time workers were looking for benefits, so it did help us on the recruiting side," she said.
One key to the success of any health care law is to connect with people in their neighborhoods or at home to explain the law and get them enrolled, said Brian Rosman, research director for the advocacy group Health Care for All.
For example, residents need to be made aware of the individual mandate, which requires virtually everyone be insured or pay a tax penalty. Massachusetts was the first state to impose the mandate, and the federal law also includes one.
About 170,000 people in the state said they were uninsured in 2010, but about two-thirds did not report enough in income and were exempt from the tax penalty.
Of the rest, there are plenty of reasons why someone might be penalized rather than have insurance, said Rosman.
Sometimes it might be due to the difficulty of reaching out to Spanish- and Portuguese-speaking populations. In other cases, he said, some people are simply philosophically opposed to being told by the government to get insurance.
The number of people assessed the penalty has fallen steadily since the law was passed, from 67,000 in 2007, the first year the mandate took effect, to 44,000 in 2010.
Gruber said the most challenging part of establishing Massachusetts' exchange was that the state was essentially starting from scratch. There was new software to be developed and critical decisions to make.
"We really were experimenting," he said. "Other states will have, in many ways, an easier time than we did."
Associated Press writer Rodrique Ngowi contributed to this report.