Nine out of 10 employers in the United States expect to be forced to change their health insurance plans under the new health care reform law, according to a new survey by Hewitt Associates, a global human resources consulting firm. Under certain circumstances, the law allows them to preserve group health insurance plans without making major administrative changes.

Almost all the 466 employers surveyed expect to lose their “grandfathered” status by 2014, and most think they'll lose it in the next two years.

The two biggest questions facing employers due to health care reform are whether they need/want to make health insurance plan changes and how they can make them without increasing costs, according to Ken Sperling, the leader of Hewitt's Health Management practice. To be eligible for grandfathered status, employers can't reduce benefits, significantly hike co-payments, raise deductibles or change insurance companies.

"Most large employers would rather have the flexibility to change their benefit programs than be tied down to the limited modifications allowed under the new law," Sperling said in a media statement.

Most employers expect to lose grandfathered status because they plan to change their health insurance plans or the amount of coverage they subsidize. Others expect to lose the status because of union negotiations, health plan consolidation or carrier changes.