Denied by a Bot? Doctors Warn AI Is Blocking Your Medicare Advantage Coverage

Medicare Advantage insurers have increasingly used artificial intelligence to decide whether to approve or deny medical services, especially for post-acute care, like stays in rehab facilities or nursing homes. Some of the largest insurers—UnitedHealthcare, Humana, and CVS—have used AI tools to speed up these decisions, which has coincided with more denials. For example, UnitedHealthcare more than doubled its rate of post-acute care denials between 2020 and 2022, during which it implemented a “machine-assisted” review process. 

These practices have drawn criticism from medical groups, including the American Medical Association, which warns that AI-driven denials can lead to unnecessary patient harm by blocking needed care. Here’s what to do if your prior authorization request is denied.

What Is Prior Authorization and Why Does It Matter?

Prior authorization is when your insurance company reviews a treatment or prescription to decide if it’s medically necessary before agreeing to pay. That means your insurer, not just your doctor, determines whether the care is covered. If the request is denied, you might have to delay treatment, pay for it yourself, or go without it.

Services that often require prior authorization include:

• Planned surgery
• Certain imaging tests
• Medical equipment

Organizations such as AHIP (America’s Health Insurance Plans), which advocates on behalf of health insurance providers, have long touted prior authorization as a means of keeping health insurance affordable. In a 2023 pamphlet, AHIP said that without prior authorization, insurers could be on the hook for unnecessary procedures that come with burdensome price tags and don’t improve health outcomes.

Yet prior authorization impacts millions of senior citizens every year, according to the non-profit organization KFF. While Medicare Advantage (MA) enrollees enjoy lower premiums and extra health care benefits, MA providers frequently require prior authorization before covering inpatient and long-term care services, with almost 50 million prior authorization determinations made in 2023. (Traditional Medicare, which is run by the federal Centers for Medicare and Medicaid Services (CMS), rarely asks for prior authorization.)

Just requiring prior authorization can create delays in people receiving care, as doctors scramble to justify their health care decisions and insurers take time to issue their final determination. Even then, more than 3.2 million prior authorization requests were fully or partially denied in 2023, per KFF data.

How AI Is Changing the Process

A Senate subcommittee report found that UnitedHealthcare, Humana, and CVS increasingly used automation and predictive technologies, including artificial intelligence, to help review prior authorization requests for post-acute care. During this period, denial rates for these services rose significantly, especially at UnitedHealthcare and Humana. The report raises concerns that these systems may prioritize cost savings over patient care, potentially making it harder for seniors to access treatment recommended by their doctors.

Asked about the use of AI in denying prior authorization requests for post-acute care, a spokesperson for AHIP said, “Health plans are responsibly using AI to enhance the consumer experience, improve care and patient outcomes, while reducing costs. We welcome the opportunity to work with policymakers on AI use in the Medicare Advantage program to ensure patients receive safe, evidence-based care while reducing low-value and inappropriate services so that coverage is as affordable as possible.”

Physicians are more skeptical. Sixty-one percent of those surveyed by the American Medical Association (AMA) expressed concern about the use of AI in denying care.

In a statement, AMA President Bruce A. Scott, M.D., said, “Emerging evidence shows that insurers use automated decision-making systems to create systematic batch denials with little or no human review, placing barriers between patients and necessary medical care.”

The accuracy of these tools is also in question. One class-action lawsuit claims insurers used an AI model despite knowing almost all of its denials were reversed on appeal.  

What to Do If Your Prior Authorization Request Is Denied

If your Medicare Advantage provider denies prior authorization for your doctor’s recommended treatment, you may still be able to appeal.

Here’s how:

1. Call your health insurance provider. You may also receive a letter from the insurer explaining its decision. Make sure you understand why the treatment or prescription was denied.
2. If any information was submitted incorrectly, you or your doctor may be able to submit revised documentation to fix the error.
3. If everything was submitted correctly, your physician may need to give the insurer a further explanation as to why you need the care they requested. Give their office a call or schedule another appointment to discuss your options.
4. You may be able to appeal as many as five times. Each appeal goes before a higher-level entity, including independent reviewers, the Office of Medicare Hearings and Appeals, the Medicare Appeals Council, and finally a federal district court for judicial review.

The Bottom Line

While prior authorization can help insurers manage costs and keep premiums more affordable, the growing use of AI in these decisions has raised concerns. Automated systems have been linked to higher denial rates for post-acute care. For many seniors, that can mean paying out of pocket or going without the care their doctors recommend.