The Top 5 Billing Errors Medical Practices Still Make in 2025

Medical billing errors remain one of the top causes of revenue loss in healthcare. Even in 2025, many practices continue to lose thousands each month due to preventable mistakes. In this post, we break down the most common billing errors we see today, why they persist, and what you can do to stop the financial bleeding.

According to a March 2024 MGMA Stat poll, 60% of medical group leaders reported an increase in their practices' claim denial rates for the current year compared to 2023. (MGMA)

Code Bundling

Let’s start with code bundling. Payers regularly deny claims when services that should be billed separately are incorrectly bundled together. While some procedures can be legitimately combined, misunderstanding bundling rules leads to underpayments or outright denials. Learn more from the AMA.

Another common issue is missing modifiers or incomplete patient data. Claims often get rejected due to small oversights like missing modifiers, incorrect birth dates, or incomplete insurance information. These errors may seem minor, but they can snowball into delayed or denied payments.

Eligibility Verification

Eligibility verification is also frequently skipped. Failing to confirm a patient's insurance eligibility before service is a simple mistake that causes a big impact. It can prevent denied claims and improve the accuracy of collected copays and deductibles.

Then there’s the problem of follow-up—or the lack thereof. Many practices either don't appeal denied claims or miss timely filing windows. Without a systematic process to monitor and resolve denials, revenue slips through the cracks.

The average denial rate for medical claims is between 5% and 10%, yet up to 50% of denied claims are never resubmitted. (Simbo.ai)

Staffing Changes

Lastly, staffing changes and training gaps present persistent problems. New billing staff or frequent turnover can result in knowledge gaps, especially when updates to coding or payer requirements aren't properly communicated. Ongoing training is essential.

Why Access1 Business Services

At Access1, we help practices identify and eliminate these issues before they impact your bottom line. Our denial prevention services include proactive monitoring, process optimization, and expert coding support.

Related: Why 89% of Denials Are Totally Preventable—But Most Practices Don’t Know How

Ready to see how much you're leaving on the table? Schedule a complimentary billing audit today.