It was not immediately clear whether the rule would help insurers hold down costs.

Karen M. Ignagni, president of America’s Health Insurance Plans, a trade group, said that in their zeal to review premiums, “the administration and Congress have largely ignored factors driving up the cost of coverage.”

These factors, Ms. Ignagni said, include the power of doctors and hospitals to negotiate higher reimbursement rates, new benefit mandates and the tendency of younger, healthier people to drop coverage, leaving sicker people in the insurance pool.

Under the proposed regulation, the federal government will assess each state’s procedures for reviewing insurance rates. If it finds that a state has an “effective rate review system,” the state would conduct the annual reviews of premium increases. But, the administration said, “if a state lacks the resources or authority to do thorough actuarial reviews, the Department of Health and Human Services would do them.”

Thus, it said, “all rate increases that meet or exceed the 10 percent threshold would be reviewed.”

The department will post information about the results of all rate reviews on its Web site, and insurers must post the data prominently on their Web sites.

States are beefing up their ability to review rates, with the help of $46 million in federal grants  the first installment of $250 million that will be distributed over five years.

Under the new federal law, insurers that show “a pattern or practice of excessive or unjustified premium increases” can be excluded from the centralized insurance market, or exchange, to be set up in each state by 2014.