Claim Denials Are Rising: Why Most Practices Are Fixing the Wrong Problem

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As of October 2026, claim denial rates are shifting in ways that catch most practices off guard. According to Kodiak Solutions’ benchmarking data covering 2,400 hospitals and 375,000 physicians, net revenue leakage from denials and uncollected balances grew 25% in 2025, reaching more than $48 billion. The growth was driven almost entirely by clinical denials, specifically claims rejected for missing prior authorizations and disputed medical necessity, not the administrative coding errors that most billing teams focus on first.

• Clinical denials are the driver. Prior authorization and medical necessity denials accounted for nearly all of the increase in denial rates, according to the Kodiak report published in 2026.
• Initial denial rates dipped, but revenue still dropped. The initial denial rate fell to 10.63% in H1 2026 from 12% a year earlier, yet net revenue leakage still grew because payers increased post-payment clawbacks.
• The fix is upstream, not downstream. Practices that address prior authorization tracking and medical necessity documentation before submission prevent the denials that rework cannot recover.

What the 2026 Denial Data Actually Shows

Kodiak Solutions released two major reports in 2026 that, taken together, paint a clear picture of where medical billing revenue is leaking. The first, the “State of the Healthcare Revenue Cycle” report published in March 2026, found that hospitals and health systems lost more than $48 billion to final claim denials and uncollected patient balances in 2025. That represents a 25% increase in net revenue leakage compared to 2024, when the figure was $38.6 billion.

The second report, “Unyielding Denials,” published in September 2026, showed that initial denial rates actually declined to 10.63% in the first half of 2026, down from 12% in the same period of 2025. At first glance, that looks like progress. The problem is that payers are not simply denying fewer claims. They are approving claims initially and then recovering revenue through post-payment audits and clawbacks. The net result is that providers collect less despite seeing fewer initial denials.

For physician practices and smaller groups, these numbers are not abstract. A practice with $2 million in annual billings and a 10.63% initial denial rate is losing approximately $213,000 in initial denials alone. If the final denial rate holds at 2.7%, the practice is permanently losing roughly $54,000 per year in revenue that could have been collected with better upstream processes.

How Are Clinical Denials Different from Administrative Denials?

Clinical denials and administrative denials require fundamentally different strategies to prevent and overturn, yet most billing teams treat them as one category. Understanding the distinction is what separates practices that recover revenue from practices that write it off.

Administrative denials are the ones billing teams have historically focused on: missing or incorrect patient demographics, wrong modifier, expired authorization number, timely filing violations, duplicate claims, and incorrect NPI. These are fixable with cleaner data entry, better charge capture, and tighter front-desk workflows. They respond well to automation and scrubbing tools.

Clinical denials are different. They include claims denied for lack of prior authorization, failure to meet medical necessity criteria, and level-of-care disputes. These require clinical documentation to prevent and clinical expertise to appeal. A CO-97 denial for a procedure that was performed without the required authorization cannot be fixed by resubmitting the claim with a corrected modifier. It requires either obtaining a retroactive authorization or building a medical necessity argument supported by clinical documentation.

Sources: Kodiak Solutions State of the Healthcare Revenue Cycle (March 2026); Kodiak Solutions Unyielding Denials (September 2026); CAQH Index 2025.

What Does a 25% Revenue Leakage Increase Mean for Your Practice?

The most common issue we see providers run into is treating denial management as an afterthought. They focus on getting claims out the door quickly and deal with denials reactively. The Kodiak data shows why that approach is failing.

Consider a multi-provider practice billing $5 million annually. At the Kodiak-reported initial denial rate of 10.63%, roughly $531,500 in claims are initially denied each year. If the practice recovers 75% of those through appeals and resubmission, it still loses approximately $132,875 annually. But here is the part most practices miss: the cost of reworking those denied claims adds an additional $13,000 to $16,000 in staff time, based on industry estimates of $25 to $30 per reworked claim. And that does not account for the post-payment clawbacks that Kodiak’s September 2026 report identified as a growing trend.

Across the billing companies we vet, the ones that deliver the strongest results for practices are the ones that invest in prior authorization tracking as a front-end process, not a back-end reaction. They verify authorization requirements before the service is rendered, document medical necessity proactively, and track payer-specific denial patterns to catch problems before they become revenue losses. The practices that come to us after experiencing a revenue dip almost always discover that their billing partner was not tracking prior authorization requirements at the payer level.

Steps to Reduce Clinical Denials Now

The Kodiak data makes the priority clear: clinical denial prevention must move from back-end rework to front-end workflow. Here is the action plan.

1. Audit your denial categories for the last 90 days. Pull your denial reports and separate clinical denials (prior auth, medical necessity) from administrative denials (missing info, coding errors). If clinical denials are your largest category, your current approach is not addressing the real problem.
2. Implement payer-specific prior authorization tracking. Each payer has different PA requirements for different services. Build or adopt a tracking system that flags authorization requirements before scheduling, not after the claim is denied.
3. Strengthen medical necessity documentation at the point of care. Clinical denials for medical necessity require documentation that justifies why the service was needed for this patient at this time. Templated notes that do not address the specific clinical rationale will not survive a payer review.
4. Monitor payer clawback activity. Per Kodiak’s September 2026 data, payers are increasingly approving claims initially and then recouping revenue through post-payment audits. Track any take-backs and appeal those that are not supported by the contract terms.
5. Evaluate whether your billing team has clinical denial expertise. Administrative denials can be managed by trained billing staff. Clinical denials require someone who understands medical necessity criteria and can build effective appeals with clinical documentation. If your current billing operation does not have that capability, it may be time to find a partner that does.

In-House vs. Outsourced Denial Management

In our experience matching providers with billing partners, the practices that struggle most with clinical denials are the ones trying to handle them with a team built for administrative billing. Administrative denial management is a volume game: scrub the claim, fix the error, resubmit. Clinical denial management is a strategy game: understand the payer’s criteria, build the clinical case, and know when to escalate to external review.

A practice billing under $1 million annually may not generate enough clinical denials to justify a dedicated denial management specialist on staff. But the cost of writing off those denials, at $50 or more per reworked clinical claim, accumulates quickly. Outsourcing to a billing company that already has clinical denial expertise, payer-specific appeal templates, and established escalation workflows can recover revenue that an in-house team is leaving behind.

The key question to ask any billing partner, whether current or prospective, is how they handle prior authorization denials specifically. Do they track PA requirements proactively? Do they have a process for retroactive authorization requests? Do they appeal medical necessity denials with clinical documentation, or do they simply resubmit and hope? The answers to those questions determine whether your billing partner is equipped for the denial landscape the Kodiak data describes, or still operating as if administrative errors are the primary problem.

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