Insurer UnitedHealth Group Inc. sees some parts of the health care overhaul as sound medicine and plans to keep them regardless of whether the law survives an upcoming Supreme Court ruling.

The nation's largest health insurer said Monday that it will still cover preventive care like immunizations without charging a co-payment, which is the fee usually paid at the doctor's office, and it will continue other popular, initial provisions of the law.

The overhaul, which aims to provide coverage for millions of uninsured people, started unfolding in 2010 after health insurers fought bitterly to block its passage. Challenges to the law from states and other groups opposed to it wound their way through the court system to the Supreme Court, which heard arguments on the law's constitutionality in March.

The court is expected to issue a ruling later this month that could strike down the entire law or parts of it or uphold it.

Despite deep divisions about President Barack Obama's law, UnitedHealth's announcement underscores the staying power of some of its reforms.

Regardless of the court's ruling, UnitedHealth will continue to offer dependent coverage to adult children up to age 26 who seek coverage through parental plans, and it won't impose lifetime dollar limits on how much an insurance policy pays out to cover claims. That can help people fighting cancer or an expensive, chronic illness.

The insurer also pledged to not pursue rescissions of individual coverage except in limited instances like cases of fraud. Rescission involves cancelling a person's coverage retroactively, sometimes after claims have been submitted.

UnitedHealth CEO Stephen J. Hemsley said in a statement that the insurer will extend some of the overhaul's initial provisions because they are good for people's health, they promote better access to quality care and they help control rising health care costs.

Preventive care like immunizations or high blood pressure screenings are touted as ways for patients to ward off bigger and costlier health care problems.

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 who pay their own medical claims and then hire an insurer to administer coverage.

The Minnetonka, Minn., insurer said its pledge focuses on elements of the law already in place. Key provisions like an expansion of the state-federal Medicaid program and tax credits to help people buy coverage won't start until 2014.

UnitedHealth also did not promise to extend another initial overhaul provision that requires the coverage of children with pre-existing conditions up to age 19. The insurer said it recognizes the provision's value, but one company alone cannot extend the provision if the law is struck down.

If only one insurer kept that provision, it might get overwhelmed with applications from children with expensive medical conditions who want the guarantee of coverage.