Some insurance provisions will stick even if law struck down

— -- Three of the nation's biggest health insurers —UnitedHealth Group, Aetna and Humana — say they will offer some benefits and consumer protections created by the U.S. health care overhaul even if the law is struck down by the Supreme Court.

Customers can keep children on their plans until age 26, get free preventive care and won't face lifetime benefit limits, no matter how the court rules, the companies said Monday. UnitedHealth and Humana also said they won't rescind policies except for cases of fraud and will retain a simplified appeals process for denials.

UnitedHealth said it can't cover children with pre-existing illnesses unless other insurers also agree to cover them and that it would work with "all other participants in the health care system" on the issue. Its statement didn't address adults with pre-existing conditions.

The Supreme Court is weighing whether a provision in the overhaul mandating that most Americans be insured is constitutional and, if not, whether to strike down the entire law or just that part of it. The law, supported by President Obama, was passed without Republican Party support.

The benefits and protections UnitedHealth would preserve probably don't cost much or add more than "a couple of dollars" to premiums, said Les Funtleyder, a portfolio manager at Miller Tabak. UnitedHealth had about 25.9 million people in its commercial plans in 2011, according to data compiled by Bloomberg.

UnitedHealth's extensions will apply largely to its customers who have individual policies or small-group health insurance through their employer, a minority of its 35 million total members. It will not include people who work for large employers that pay their own medical claims and then hire an insurer to administer coverage.

The insurer said its pledge focuses on parts of the law in effect. Key provisions, such as an expansion of the state-federal Medicaid program and tax credits to help people buy coverage, won't start until 2014.

The requirement that insurers allow families to keep children in their plans until age 26 expanded insurance coverage to about 2.5 million people in 2011 while increasing premiums less than 1%, the government estimates.

The provision is among the most popular parts of the law, polls show, and the non-profit Commonwealth Fund in New York estimated last week that about 6.6 million young adults are on their parents' plans because of it.