Insurer UnitedHealth Group Inc. sees some parts of the health care overhaul as sound medicine and plans to keep them even if the law fails to survive 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.

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.