The largest health insurers in the United States are promising to reduce and improve a widely disdained practice that leads to delays and complications in care.

UnitedHealthcare, CVS Health's Aetna and dozens of other insurers say they plan to reduce the scope of health care claims subject to prior authorization, standardize parts of the process and expand responses performed in real time.

Prior authorization means insurers require approval before covering medical care, a prescription, or a service like an imaging test. Insurers say they do this to prevent health care abuse and ensure patients receive the right treatment.

But doctors say the practice has grown in scope and complexity, leading to frequent delays in care.

The fatal shooting of UnitedHealthcare CEO Brian Thompson in December led many to express frustration over coverage issues like prior authorization. Major health insurers had previously promised to review the paperwork-laden process, but little has changed.

Dr. Mehmet Oz, who now oversees the Centers for Medicare and Medicaid Services, said Monday that insurers are motivated to do something lasting this time.

“There is violence in the streets because of this,” Oz said during a news conference Monday, hours after meeting with most of the major U.S. insurers. “Americans are outraged by this.”

Insurers announced Monday that they will standardize electronic prior authorization by the end of next year to streamline the process. They will narrow the scope of claims subject to medical prior authorization and will honor preapprovals from a previous insurer for a certain period after someone switches plans.

They also plan to expand the number of real-time responses and say they will ensure that claims denied for clinical reasons continue to be reviewed by “medical professionals.” However, they did not promise that those reviewers would be from the same specialty as the attending physician, a common complaint among doctors. Insurers have promised to make the changes voluntarily, but Oz said the Trump administration will review regulations if progress is not made. “You fix it or we’ll fix it,” Oz said. Researchers say prior authorization has become more common as health care costs have risen, especially for prescription drugs, lab tests, physical therapy and imaging exams. “We’re in a bit of a catch-22 situation between the unaffordability of care and the worsening of these nonfinancial barriers and administrative burdens,” said Michael Anne Kyle, an assistant professor at the University of Pennsylvania who studies how patients access care. Nearly all customers in Medicare Advantage plans, the private version of the federal government’s Medicare program, need prior authorization for some services, particularly for expensive care like hospitalizations, the health policy research organization KFF found in a 2023 claims study. The study also found that insurers denied about 6% of all claims.

Dr. Ashley Sumrall of Charlotte, North Carolina, says she's seen an increase in the number of prior authorizations required for routine tests like MRIs. Sumrall, an oncologist who specializes in treating brain tumors, said such images are crucial for doctors to determine if a treatment is working and plan next steps.

Doctors say delays in claims that are ultimately approved or coverage denials can harm patients by allowing the disease to progress without treatment. They can also increase anxiety in patients who want to know if their tumor has stopped growing and if insurance will cover the ultrasound.

“There’s a term we use called ‘scan anxiety,’ and it’s very real,” said Sumrall, a volunteer leadership member for the Association of Clinical Oncology.

Different forms and prior authorization policies also complicate the process. Sumrall noted that each insurer “has its own way of operating.”

“For years, companies have been unwilling to make concessions, “So I think any step toward standardization is encouraging,” he said. Insurers say their promises will apply to coverage through work or the individual market, as well as Medicare Advantage plans and the state- and federally-funded Medicaid program.