An increasing number of denied health insurance claims are being overturned when challenged, offering a clearer picture of how often initial coverage decisions may be reversed and what that means for providers, patients, and ultimately collections. A new study analyzing more than 51,000 external appeals in New York found that nearly half of denials were overturned, with rates climbing significantly in recent years. For professionals dealing with unpaid medical debts, the findings highlight a key upstream factor: many balances may originate from denials that do not hold up under further scrutiny.
The data shows that 46.7% of external appeals were overturned overall, with success rates rising from 38% in 2019 to more than 52% in 2025 . Appeal volume also more than doubled during that time, signaling both increased patient and provider willingness to challenge denials and potential systemic issues in initial claim determinations.
The financial implications are hard to ignore. When claims are denied but later overturned, patients may initially receive bills they believe they owe, only for those obligations to disappear after appeal. That creates volatility in receivables for healthcare providers and complicates downstream collection strategies.
Key findings from the study include:
- Home healthcare denials were overturned at a rate of more than 78%, the highest among analyzed categories
- More than half of denials related to prescription drugs, dental procedures, and surgeries were reversed
- Mental health and substance abuse treatment denials were overturned roughly 60% of the time
- Cancer-related denials were overturned in about 45% of cases
The likelihood of reversal also varied significantly by insurer, ranging from roughly 36% to as high as 85%, suggesting inconsistencies in how coverage determinations are made across plans.
For providers and revenue cycle teams, this reinforces the importance of a strong appeal process. Claims that are written off or sent to collections too early may still have a high probability of being paid if properly challenged. For collection agencies and debt buyers, it introduces another layer of risk: some accounts may be tied to balances that were never truly valid.
Researchers pointed to several possible causes behind the high overturn rates, including human error, outdated clinical criteria, and inconsistent application of coverage rules. They also noted that independent clinical reviewers play a significant role in reversing decisions, particularly at the external appeal level.
The broader takeaway is that denial management is not just a compliance or operational issue, it is directly tied to revenue integrity. As policymakers continue to examine insurer practices, and as appeal volumes grow, stakeholders across the healthcare and collections ecosystem may need to rethink how they evaluate and act on denied claims before they become patient debt.
