If the Affordable Care Act, or even parts of it, is upheld, Americans will be able to opt for health care outside of their job. How will employees respond?

FORTUNE -- How many people do you know who take a job or stay at one for the health benefits? Many do.

"Today, employees really don't have a lot of choices besides the plans that their own employers sponsor," says Sandy Ageloff, the southwest health and group benefits leader at Towers Watson. And employment-based health benefits insure well over half of the of the country's nonelderly citizens, according to an April 2012 study by the Employee Benefit Research Institute.

But that may change, depending on the Supreme Court's ruling on the Affordable Health Care Act, which should come later this month. There are several potential outcomes: the Court may give the act a full go-ahead, it could strike it down whole hog, or some parts may be upheld while others -- particularly the individual mandate, which requires just about every American to purchase some form of health coverage -- may get the boot.

One signature part of the Affordable Care Act is that by 2014, states are required to create health insurance exchanges, which are intended to provide an affordable alternative to individual and company-sponsored insurance plans. So, what happens to the workforce when employees no longer feel tied to jobs for the health benefits?

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Currently, company-provided health insurance contributes to a kind of job-lock in the U.S. "This is a big thing," says Aparna Mathur, an economist and resident scholar at the American Enterprise Institute. "We are seeing inefficiencies in the labor market in the sense that there are vacancies out there, but mobility is really low because people are uncertain if they should be switching jobs."

Theoretically, options for health insurance outside of employer-offered plans could free up the workforce. "Definitely if you had health insurance that was mobile, you would see more efficiency in the labor market, people could transition to the best job possible," Mathur says, instead of being cautious about switching jobs because of uncertainty about benefits.  More