Insurance denials of cancer care: Insights from Medicare claims appeals.

204 Background: Managed care plans employ utilization management tools—such as prior authorization—with a goal to steer patients away from costly and low-value care. However, these tools may impede access to necessary care and adversely impact patient outcomes. While care delays and denials are common in oncology, less is known about how plans restrict care. In this study, we seek to provide more granular insights into care denials for cancer-directed systemic therapies by analyzing claim appeals in Medicare Part C (Medicare Advantage) and D (Medicare’s outpatient prescription drug benefit). Methods: We analyzed publicly available records of appealed Medicare claims, which are adjudicated by an external review entity following initial denials by Medicare plans (i.e., Level 2 review), from 2020 to 2025. We included claims appeals for cancer-directed systemic therapies (N = 11,852). Using a natural language process (NLP) algorithm, we extracted the following information from the text of each record: cancer site, treatment, rationale for the initial denial, appeals status (favorable/unfavorable), and the level of patient’s clinical details contained in the appeals decision summary (low/moderate/high, assessed by the NLP model). In this abstract, we summarize preliminary findings from a < 1% random sample of Part D appeals (full results will be available at the conference). Results: Of the sample of records analyzed (n = 48), over 17% of initially denied claims were successfully overturned (the rate of successful appeals among claims for non-cancer care is 6%). Overall, prostate (29%), breast (15%), and lung (15%) cancers were the top 3 cancer sites reported on denied claims. Most claims were initially denied for treatments not meeting the medical necessity criteria (50%) or being prescribed off-label (31%). For these claims, the decision summary primarily noted either lack of supporting citations in Medicare-approved compendia (73%) or failure to supply other peer-reviewed evidence (30%) as reasons for unfavorable review. All successful appeals were ranked as containing “high” level of clinical details, whereas unsuccessful appeals were mostly categorized as having “low” or “moderate” level of details (25% and 65%, respectively). Conclusions: Overturned denials may indicate that many cancer care claims were initially wrongfully denied by Medicare plans. In such cases, initial denials and efforts to reverse them likely imposed significant administrative burdens for patients and clinicians. At the same time, unfavorable appeals were frequent due to failure to demonstrate medical necessity or off-label use. To facilitate high-value and timely cancer care, a more streamlined and clear process for adjudicating the clinical appropriateness of cancer treatments is imperative.