Millions of Americans might be eligible for rebates starting in 2012 under regulations released Monday detailing the health care law’s requirement that insurers spend at least 80 percent of their revenue on direct medical care.

The regulations closely follow recommendations sent to the U.S. Department of Health and Human Services by the National Association of Insurance Commissioners (NAIC) after months of meetings and debate involving industry and consumer representatives.

The government estimates that 45 percent of people who buy their own coverage are in plans that currently don’t meet the standard. If the law were in effect now, about 9 million would get rebates, either directly, if they buy their own coverage, or through their employers if they are in job-based coverage.

“This will guarantee that consumers will get the most out of their premium dollars,” HHS Secretary Kathleen Sebelius said at a news conference Monday.

The law applies to policies sold to individuals as well as those sold through employers. The 80 percent standard applies to individual and small group policies. Larger group policies – generally considered to be more than 50 people – must spend at least 85 percent of revenue on care.

There are some exemptions:

— Employers and insurers that offer “mini-med” policies, which are plans that limit coverage to $250,000 a year or less, get a special way to calculate their medical spending next year: They’ll total the amount spent on doctors, hospitals and other medical and quality improvement expenses, then multiply that figure by 2. In effect, that will allow them to meet the 80 percent ratio by spending as little as 40 percent on medical costs. HHS will revisit that provision after 2011.

— States may apply to have the requirement adjusted if meeting the 80 percent spending require would destabilize their individual market, Sebelius said. Four states – Maine, Iowa, South Carolina and Georgia – have already said they would seek adjustments.

— Some small plans will not have to provide rebates, at least for the first year.

During the debate leading to the NAIC’s recommendations, insurers pushed for the broadest possible definition of what constitutes medical spending, including the cost of paying claims, signing up doctors to their networks or running customer service call centers. The final recommendations are narrower, which is what consumer groups had urged.

The regulations allow, for example, insurers to include many quality improvement costs, along with payments to doctors, nurses, hospitals and other providers in their medical expense calculations but not the cost of broker commissions.

Consumer advocates were pleased.

“Few Americans understand how much of what they spend on health insurance goes to administration,” said NAIC consumer representative Timothy Jost, a law professor at Washington and Lee University School of Law.

Currently, he said, insurers covering 20 percent of Americans spend about 30 percent of their revenue on administrative costs, a percentage that will result in rebates unless they reduce those costs.

Insurers, who had objected  strongly to the NAIC recommendations, toned down their criticism Monday, saying the new rules “take a first step” toward minimizing market disruption for plans sold to individuals, but said there remains a potential that the rules could affect employer-offered coverage.

When the NAIC sent recommendations to Sebelius in October, insurers objected.

The recommendations, would “reduce competition, disrupt coverage and threaten patients’ access to health plans’ quality improvement services,” America’s Health Insurance Plans president and CEO Karen Ignagni said in a in October.