Warren, Senators Push Dr. Oz to Tackle Medicare Advantage Abuse

Warren, Senators Push Dr. Oz to Tackle Medicare Advantage Abuse

Senators call to rein in private health insurers' abuse in Medicare as Trump Administration explores options to automatically enroll seniors into the program.

"As Americans struggle to keep up with rising health care costs, [Medicare Advantage] insurers continue to rake in billions in overpayments, abusing taxpayer dollars."

Text of Letter (PDF)

Washington, D.C. - U.S. Senator Elizabeth Warren (D-Mass.) led seven other senators in urging Dr. Mehmet Oz, the Administrator of the Centers for Medicare and Medicaid Services (CMS), to hold health insurers accountable for persistent abuses in the Medicare Advantage program that raise costs and lower quality of care for millions of seniors and people with disabilities. This comes as the Trump Administration is reportedly exploring options to automatically enroll seniors and people with disabilities into the program.

"As Administrator of the Centers for Medicare and Medicaid Services, you have withheld essential funding for seniors and people with disabilities and slashed Medicaid under the guise of rooting out waste, fraud, and abuse," wrote the senators. "However, legitimate fraud, waste, and abuse in Medicare Advantage remains largely unchecked."

Unlike traditional Medicare, which infrequently requires prior authorization for services, nearly all Medicare Advantage enrollees are "required to obtain prior authorization for some services." In 2024, Medicare Advantage insurers either fully or partially denied around 4.1 million prior authorization requests - over 27 times the number of denials in traditional Medicare. As a result, 93 percent of physicians have reported that prior authorization delayed patients' access to critical care, and over three quarters of physicians reported that these requirements likely contributed to patients abandoning their treatment.

"Rather than hold insurers accountable through regulation, your agency has proposed to remove multiple administrative measures from the star ratings system that indicate complaints regarding the timeliness or accuracy of prior authorizations, while also expanding prior authorization in traditional Medicare," continued the senators.

Individuals enrolled in Medicare Advantage also face restricted networks that create significant barriers to care. This is especially true in counties with a higher proportion of people of color, in which just 37% of physicians are considered in-network for seniors and people with disabilities enrolled in Medicare Advantage. The senators note that this is a matter of life or death for some patients, especially those with cancer. Medicare Advantage plans often exclude cancer research centers, leading many enrollees to lose access to clinical trials, advanced treatments, and radiation.

On January 26, 2026, CMS released a proposed payment rule that would increase payments to Medicare Advantage insurers by $700 million in CY 2027, all while seniors and people with disabilities enrolled in the program face greater barriers to care, more delays and denials, and higher costs.

To prevent insurance companies from further abusing the Medicare Advantage program, the senators expressed the need for the following actions:

1. Further reduce overpayments from risk adjustment and favorable selection;

2. Prevent insurance companies from denying medically necessary services; and

3. Hold MA insurers accountable for engaging in anti-competitive behavior and evading regulatory protections.

"As Americans struggle to keep up with rising health care costs, [Medicare Advantage] insurers continue to rake in billions in overpayments, abusing taxpayer dollars, while inappropriately obstructing enrollees from accessing medical care," concluded the senators. "We urge CMS to turn its focus to the legitimate fraud, waste, and abuse in Medicare Advantage and address the program's longstanding problems that prevent seniors and people with disabilities from receiving medically necessary care."

The letter was also signed by Senators Bernie Sanders (I-Vt.), ranking member of the Senate Health, Education, Labor, and Pensions Committee; Edward Markey (D-Mass.); Richard Blumenthal (D-Conn.); Jeff Merkley (D-Ore.); Tina Smith (D-Minn.); Richard Durbin (D-Ill.); and Cory Booker (D-N.J.).

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