June 23 (Reuters) - America's Health Insurance Plans said on Monday that U.S. health insurers will take additional measures to simplify their requirements for prior approval on medicines and medical services.

Health insurers will work to develop standardized data and submission requirements for electronic prior authorization by January 1, 2027, the industry trade group said in a statement.

The firms will also work on reducing the scope of claims that require prior authorization by January 1, 2026, and ensure the authorizations are valid for a 90-day period if the patient changes insurance companies during the course of treatment.

U.S. Health and Human Services Secretary Robert F. Kennedy, Jr. and Centers for Medicare and Medicaid Services Administrator Mehmet Oz are scheduled to discuss health insurance reforms in a press conference later in the day.

"The health care system remains fragmented and burdened by outdated manual processes, resulting in frustration for patients and providers alike," AHIP CEO Mike Tuffin said.

Separately, CVS Health's CVS.N insurance unit Aetna announced a series of measures on Monday.

This included the move to bundle multiple authorization requests into one upfront approval for people with lung, breast or prostate cancer who need such authorizations for MRI or CT scans.

The killing of the head of UnitedHealth's UNH.N insurance unit last year had ignited significant social media backlash from Americans struggling to receive and pay for medical care.

UnitedHealth had said in March it would ease requirements to get insurance authorization when renewing prescriptions on about 80 drugs, aiming to eliminate up to 25% of reauthorization requirements.

(Reporting by Mariam Sunny in Bengaluru)

((Mariam.ESunny@thomsonreuters.com;))