How the federal health law will affect premiums is among the most asked – and most controversial – questions in the final months before new rules kick in requiring most Americans to carry coverage.

A white paper out Wednesday considers how the law will affect premiums for people who buy their own coverage because they don’t get it through their jobs. The answer?  It all depends, said the analysts at the Kaiser Family Foundation. (KHN is an editorially independent program of the foundation.)

The paper says the law’s provision that limits premiums for older consumers to no more than three times what younger people pay will mean those younger beneficiaries, particularly men, will pay more than they do now.  Older people and many women will see lower rates, the paper says.

At the same time, broader benefit packages than are often purchased by individuals today, limits on deductibles and other costs and rules that bar insurers from rejecting people with pre-existing medical conditions will also cause premiums to rise compared with what they would have done without the law.

Starting in 2014, for example, policies must include coverage for maternity care, prescription drugs and mental health treatment, benefits that often are not included in policies purchased by individuals today .

“The more complete benefits will increase premiums when compared to current nongroup policies because there is more coverage,” the paper says.

“It’s not that we should not be concerned about how much some people will have to pay for insurance under reform, but concerns about sweeping rate shock are exaggerated,” said Larry Levitt, a senior vice president at the foundation and one of the co-authors of the report. “Subsidies are by far the biggest factor that cushions the impact of any increases in premiums people might see.”

The paper does not estimate how much premiums will increase.  Reports from the Congressional Budget Office in 2009, however, projected that premiums for individuals who buy their own coverage could go up 10 to 30 percent because of the law’s rules. More recent surveys by consultants and insurers have speculated that premiums could rise far higher than that, depending on a person’s age and health. A 27-year-old, for example, could see an average increase of 169 percent in five markets surveyed by the conservative American Action Forum.

Still, Kaiser Family Foundation researchers and others have said that federal subsidies available to low- and moderate-income Americans are likely to offset the increases for many consumers.  The rules on how much premiums can vary among younger and older consumers, for example, are likely to be offset by subsidies for about 80 percent of those currently in the individual market, according to the paper.

“While many younger enrollees would see higher premiums under the three-to-one age limit, they would not pay more because they would receive a tax credit that caps their premium obligation as a percentage of their income,” the paper says.

But that solution raises other concerns, said consultant Robert Laszewski, a former insurance industry executive.

“A lot is made of the fact that federal subsidies will offset (the increases), but there is no Santa Claus,” he said. “Consumers will have much of these increases mitigated and taxpayers will pay for them.”

Insurers, along with some lawmakers and advocacy groups for young people, are urging that the ratio rule be phased in slowly. Most states allow wider variations now – or set no limits at all.

A bill formally introduced Wednesday by Rep. Phil Gingrey, R-Ga., would allow states to set their own ratio.  It has already drawn opposition from AARP, which represents older Americans and which argues it would “be a huge step backward” to allows insurers to continue “the discriminatory practice of charging exorbitant premiums to older Americans.”

The federal health law does allow insurers to sell special policies to Americans under 30 that would provide limited catastrophic coverage in exchange for what are expected to be lower premiums than other types of policies. People buying those policies, however, would pay higher deductibles and are not eligible for federal subsidies.