Deny First, Approve Later?

New Federal Findings Raise Questions About Whether Medicare Advantage Prior Authorization Is Functioning as a Clinical Safeguard—or a Cost-Control Tool

Medicare Advantage insurers have defended prior authorization as a necessary mechanism to ensure that care is medically appropriate, evidence-based, and cost-effective. Federal regulators have generally accepted that premise. The assumption underlying prior authorization has always been straightforward: some requests should be denied because they do not meet clinical criteria. But what happens when insurers reverse nearly all of those denials after an appeal?

A pair of new reports from the U.S. Department of Health and Human Services Office of Inspector General (OIG) raises precisely that question—and the answers may be uncomfortable for the Medicare Advantage industry. The reports found that some of the nation’s largest Medicare Advantage insurers denied post-acute care requests at extraordinarily high rates, only to later overturn many of those same decisions when challenged.

The findings do not prove that insurers intentionally deny medically necessary care. They do, however, challenge the assumption that current prior authorization practices are consistently identifying inappropriate care.

The Most Vulnerable Patients Are at the Center of the Controversy

The OIG focused on a particularly sensitive segment of healthcare: post-acute care. These are patients who have already experienced a serious illness, surgery, injury, or hospitalization and require additional treatment before they can safely return home.

The review examined requests for admission to long-term acute care hospitals (LTCHs), inpatient rehabilitation facilities (IRFs), and skilled nursing facilities (SNFs). These settings are often used by patients recovering from strokes, major surgeries, traumatic injuries, severe infections, or other complex medical conditions.

In other words, this is not elective care. These are often patients in medically fragile conditions whose recovery trajectories can be significantly influenced by delays in treatment or rehabilitation. That context makes the denial data particularly noteworthy.

Three Insurers Stood Apart from the Rest

The OIG analyzed data from 19 Medicare Advantage organizations representing approximately 29.3 million beneficiaries—about 86% of Medicare Advantage enrollment at the time.  Across the industry, denial rates were substantial. Insurers collectively denied nearly two-thirds of requests for long-term acute care hospitals and more than half of requests for inpatient rehabilitation facilities.

Yet the most striking finding was not the overall denial rate. It was where those denials were concentrated.

According to OIG, the three largest Medicare Advantage organizations by enrollment—UnitedHealth Group, Humana, and CVS Health—denied requests for post-acute care at rates significantly higher than most competitors. Each denied more than 70% of requests for long-term acute care hospitals and more than half of requests for inpatient rehabilitation facilities.

Because these insurers collectively cover roughly 20 million Medicare Advantage members, their practices have an outsized effect on beneficiary access nationwide.

The Appeal Data May Be the Most Important Finding

The denial rates alone would likely have generated concern. The appeal data generated something more serious. For skilled nursing facility admissions, Medicare Advantage organizations denied approximately 12% of requests overall. Beneficiaries or providers appealed only about 18% of those denials. Yet when appeals occurred, insurers overturned 95% of denied requests.  Ninety-five percent. That figure presents a challenge to the industry’s narrative.

If the overwhelming majority of appealed denials ultimately result in approval, one of two conclusions becomes difficult to avoid. Either the original denials were frequently incorrect, or the appeal process is introducing entirely new information that was unavailable during the initial review.

The OIG explicitly stated that the exceptionally high overturn rate raises concerns that some beneficiaries were initially denied medically necessary care. The implication is significant.

Prior authorization is often justified as a quality control mechanism. Yet a process that reverses nearly every challenged decision begins to resemble an administrative hurdle rather than a clinical safeguard.

The Hidden Problem: Most Patients Never Appeal

The most troubling aspect of the OIG findings may not be the denials themselves. It may be the appeals that never happen. Only a minority of beneficiaries challenge adverse decisions. For long-term care and rehabilitation admissions, approximately one-third of denials were appealed. For skilled nursing admissions, fewer than one in five denials were challenged.  This means the vast majority of denied patients never reach the stage where insurers frequently reverse their decisions. Why?

For many beneficiaries, particularly older adults recovering from hospitalization, the appeals process can be difficult to navigate. Time-sensitive care needs, administrative complexity, health literacy barriers, and physical limitations all reduce the likelihood that a patient will challenge a denial. As a result, the practical impact of an inappropriate denial may be determined less by clinical necessity than by a patient’s ability to navigate an appeals system.

A Pattern Regulators Have Been Tracking for Years

The OIG reports did not emerge in a vacuum. Federal watchdogs have repeatedly raised concerns about Medicare Advantage prior authorization practices.

A landmark OIG review in 2022 found that some Medicare Advantage plans denied services that met Medicare coverage rules and would likely have been approved under traditional Medicare. Subsequent investigations have continued to focus on post-acute care as an area of particular concern.

Congressional investigators have also examined the growing use of predictive technologies and algorithmic decision-support systems in prior authorization workflows. Critics argue these tools may increase denial rates while distancing clinical decisions from individualized patient assessment.  The latest OIG findings add another layer to that debate. The issue is no longer simply whether denials occur. The issue is whether denial systems are accurately identifying unnecessary care in the first place.

The Economic Incentive Problem

From a policy perspective, the reports highlight an inherent tension within Medicare Advantage. Insurers receive fixed payments from the federal government to manage beneficiary care. That structure creates incentives to coordinate care efficiently and avoid unnecessary utilization.

However, it also creates incentives to limit spending. Prior authorization sits directly at the intersection of those competing objectives. Every denial may represent either appropriate utilization management or inappropriate restriction of care. The challenge for regulators is determining where that line exists.

The OIG findings do not establish that insurers systematically deny care for financial reasons. However, they do suggest that current oversight mechanisms may not be adequately distinguishing between clinically justified denials and those that should never have occurred.

When denial rates are high and overturn rates are even higher, regulators inevitably begin asking whether utilization management has drifted beyond its intended purpose.

Why This Matters for the Future of Medicare Advantage

The timing of the reports is significant. Medicare Advantage now covers more than half of all Medicare beneficiaries, and enrollment is projected to continue growing over the coming decade.  As the program expands, prior authorization becomes more than an insurer operational issue. It becomes a national access-to-care issue.

The OIG findings are likely to intensify calls for reforms already being debated in Congress and at CMS, including greater transparency around denial rates, stronger reporting requirements, faster appeals processes, and tighter oversight of utilization management practices.

The industry’s challenge will be demonstrating that prior authorization remains a legitimate clinical review process rather than a mechanism that delays care until patients or providers are willing to fight back.

The Bigger Question

The new OIG reports do not prove that Medicare Advantage plans are routinely denying care for profit. But they do expose a troubling disconnect. If an overwhelming share of appealed denials ultimately become approvals, then the central question is no longer whether prior authorization creates administrative burden.

The question is whether the system is accurately identifying inappropriate care at all. For policymakers, that distinction matters enormously. A utilization management system that occasionally makes mistakes is expected. A utilization management system that routinely reverses its own decisions after appeal raises a far more fundamental concern: whether the denial itself has become part of the process.

Sources

1. HHS OIG. The Three Largest Medicare Advantage Organizations Denied Requests for Long-Term Acute Care and Inpatient Rehabilitation at Some of the Highest Rates. June 2026.
2. HHS OIG. Medicare Advantage Organizations Overturned Nearly All Appealed Prior Authorization Denials for Skilled Nursing Facility Admission. June 2026.
3. Healthcare Dive. Major Medicare Advantage insurers appear to deny care for profit, federal watchdog finds. June 2026.
4. Fierce Healthcare. OIG: Frequent MA prior authorization denials for long-term care hospitals, inpatient rehab. June 2026.
5. American Academy of Physical Medicine and Rehabilitation. HHS OIG Reports Highlight Need for Prior Authorization Reform. June 2026.
6. OIG Work Plan: Medicare Advantage Organizations’ Use of Prior Authorization for Post-Acute Care.