Those shortcomings have fueled steady criticism from national conservatives, who derisively label the Massachusetts overhaul "RomneyCare" to parallel the "ObamaCare" epithet Republicans use for the federal law.
In his latest book, former Arkansas Gov. Mike Huckabee, a potential 2012 GOP presidential contender, said the people of Massachusetts had "participated in an experiment that blew up in their faces."
Former Minnesota Gov. Tim Pawlenty, the first Republican to formally enter the race, last year said Massachusetts was not a model "I would want for the country to follow."
In Massachusetts, that kind of criticism is harder to find. Popular support for the overhaul remains high, as does support among stakeholders like doctors.
"There's a lot of pride that we did something that no other state has done," said Dr. Alice Coombs, president of the Massachusetts Medical Society. "And physicians like the fact that they can focus on caring for patients, not worrying about who has insurance."
And while state healthcare spending has surged as people lost their jobs in recent years, the law has not blown a hole in the state budget, according to a 2009 analysis by the fiscally conservative Massachusetts Taxpayers Foundation. The group concluded that out of a state budget of $30 billion, the coverage expansion added just $88 million a year to state spending over the first four years.
"The distortions are just amazing," said Widmer of the taxpayers foundation. "It just hasn't broken the bank. That's a myth."
Even business and insurance industry leaders now pushing for more aggressive steps to restrain costs say other factors — such as the economy and the power wielded by hospitals in Massachusetts — are the primary causes for surging insurance premiums.
"Double-digit rate increases have nothing to do with health reform," said Richard Lord, president of Associated Industries of Massachusetts, the state's largest business group.
Lord is among a group of state leaders, including Romney's successor Gov. Deval Patrick, who are now turning to the more difficult task of taming rising healthcare spending.
That wouldn't have been possible without the 2006 reforms that Romney championed, said Tim Gens, executive vice president of the Massachusetts Hospital Assn.
"People have more access to care now. That's not just better for individuals.... It laid the groundwork for being able to reform the payment and delivery system," he said. "Gov. Romney deserves credit for helping to get that ball rolling."