(Bloomberg News) Three of the top five U.S. health insurers sent a signal that many of the changes wrought by the 2010 health-care overhaul are here to stay, even if the Supreme Court decides the law itself must go.

UnitedHealth Group Inc., Aetna Inc. and Humana Inc. said this week they would save some of the law's most popular provisions, including letting young adults stay on parents' plans. Employers seeking to contain the cost of care will also press to keep other provisions, said Mike Tuffin, who represented insurers as executive vice president at America's Health Insurance Plans while the law was being negotiated.

"One way or another, some of these pieces will either be re-instituted or remain in effect through the actions of the private marketplace," Tuffin said in a telephone interview.

Insurers and regulators have begun implementing the law that will produce the biggest changes in health care since the advent of Medicare and Medicaid in the 1960s. Some provisions may be nullified when the Supreme Court rules this month on whether the law's requirement that most Americans carry insurance is constitutional. UnitedHealth, Humana and Aetna were applauded by the head of the Robert Wood Johnson Foundation for refusing to "be held hostage by the political and judicial process."

"I would hope that the others would follow suit," Risa Lavizzo-Mourey, president and chief executive officer of the Princeton, New Jersey-based research and advocacy group, said in a telephone interview. The provisions the insurers plan to retain will expand coverage and "pay off in the long run."

Lifetime Benefits

At stake is a law that would expand insurance to at least 30 million people and transform an industry that accounts for 18 percent of the U.S. economy. A ruling striking down all or part of the law may come on a 5-4 vote, with the Republican-appointed Supreme Court justices in the majority and the Democratic appointees in dissent. Republicans, including presidential candidate Mitt Romney, have called for a repeal.

UnitedHealth, Aetna and Humana said in separate statements that they would keep simplified, independent reviews of appeals of coverage denials regardless of the court's decision. Minnetonka, Minnesota-based UnitedHealth and Louisville, Kentucky-based Humana said they would also end rescissions, or retroactive terminations of policies, except in cases of fraud, and eliminate dollar limits on lifetime benefits in their plans. The three companies have a total of at least 48 million customers on their commercial health plans.

The companies "want to send a strong message to their customers that their coverage, the benefits their customers have today, will remain in effect regardless of how the court rules," said Tuffin, who is now managing director of the Washington office for APCO Worldwide, a consulting firm.

Young Adults