The new health care law will add 32 million people to the rolls of the insured. But that won’t work well if they can't get access to a doctor. And many say the U.S. is facing a growing shortage of physicians.

"And that is going to ... put tremendous pressure on the system to handle all the new people that are enrolled," says Grace-Marie Turner, president of the Galen Institute and author of "Why Obamacare Is Wrong for America."

The Association of American Medical Colleges predicts that by 2015, there will be a shortage of more than 62,000 doctors. By 2020, the shortage leaps to more than 91,000, and by 2025, it is more than 130,000.

One analyst likened the health care law to giving everyone a free bus pass -- but without enough buses.

"If you cover them all, it gives them the pass, but you then have to connect that to a workforce solution that appropriately provides that access of care to them," said Dr. Roland Goertz, president of the American Academy of Family Physicians.

There are several reasons for the shortage.

First, 10,000 baby boomers retire every day and seniors use more health care. Second, many doctors are boomers themselves. And one-third of doctors are expected to retire in the next 10 years.

And on top of all that is the new health care law, which would expand coverage.

"You're going to wind up with medical practices looking like assembly lines," Turner predicted.

Neera Tanden, now at the Center for American Progress, worked on the health care law when she was a member of the Obama administration. She said they were concerned about that "you'd have an increase of demand because we have higher rates of insurance," as 32 million more became insured.

But she also said the law doesn't create demand for health care that wasn’t already there.

"It's not like we are creating 30 million new patients, new consumers in the health care system," she said. "People who are uninsured still use the health care system. They just use it in a very inefficient way."

By going to emergency rooms for instance. But the law did create some assistance for aspiring primary care doctors, which medical groups cautiously welcome.

"Now, is that enough? That's the question. I think it's a step in the right direction," said Goertz, whose organization represents primary care physicians.

One other aspect of the new law is that 16 million of those who gain insurance are pushed into Medicaid, health care for the poor.

Turner said the result of that "is going to be longer waiting lines. Already Medicaid pays so little in so many states that people simply can’t find a private physician to see them."

The new law also seeks to save money in Medicare by reducing reimbursements there too. Officials argue that can be done with more efficient care, but some fear that could make it harder for seniors to find a doctor as well.

Some analysts warn that unless this problem is solved, access to insurance wouldn't automatically mean access to better care.