Why Your Practice Is Leaving Money on the Table with Under-Coding

Published April 4, 2026 · 9 min read · By RCMAXIS Revenue Cycle Team

Under-coding is the silent revenue killer in specialty practices. While everyone fears upcoding audits, the AAPC reports that under-coding is 3x more prevalent than upcoding across US medical practices. The Office of Inspector General (OIG) has repeatedly noted that coding conservatism costs the healthcare system accuracy, not just revenue.

What Is Under-Coding?

Under-coding occurs when a provider or coder selects a CPT or E/M code that represents a lower level of service than what was actually performed and documented. Common examples include billing a Level 3 office visit when documentation supports Level 4, or using a basic fracture care code when the procedure involved internal fixation.

Under-coding is not conservative compliance. It is inaccurate coding. The CPT guidelines are clear: the code should reflect the service provided. Billing lower than documented is a coding error, just like billing higher.

Where Under-Coding Happens Most

E/M Level Selection

According to CMS utilization data, 68% of all office visits are billed as Level 3 (99213/99203). Yet clinical documentation audits consistently show that 30-40% of those visits meet Level 4 criteria. For a provider seeing 25 patients daily, this coding gap equals approximately $150-$250 per day in lost revenue, translating to $37,500-$62,500 annually per provider.

Surgical Procedures

Specialty surgical practices frequently under-code by failing to bill separately for distinct procedures performed during the same session. As we found in our orthopedic case study, a 4-provider group recovered an additional $180,000 annually simply by correcting modifier usage and unbundling legitimately distinct procedures.

Ancillary Services

In-office diagnostics, lab work, and procedures performed alongside E/M visits are frequently unbilled. Practices commonly perform EKGs, spirometry, or point-of-care testing without capturing the charge. MGMA estimates that 12-18% of ancillary revenue goes uncaptured in typical practices.

The Psychology Behind Under-Coding

Under-coding persists because of fear, not negligence. Providers worry about:

• Audit anxiety: Fear of being flagged as an outlier by payers or CMS
• Insufficient documentation training: Providers who document thoroughly but code conservatively
• Lack of coding education: Providers selecting familiar codes rather than learning updated options
• Risk-averse billing staff: In-house billers who default to lower codes to avoid denial rework

How to Fix Under-Coding Without Compliance Risk

1. Conduct a Coding Audit

Pull a random sample of 50 charts per provider. Compare the billed code against documentation using current CPT guidelines. Calculate the percentage of under-coded vs. accurately coded vs. over-coded encounters. Most practices discover a 20-35% under-coding rate.

2. Implement Real-Time Coding Feedback

Rather than retrospective audits alone, integrate coding suggestions into your EHR workflow. Modern PM systems can flag when documentation supports a higher-level code than what the provider selected.

3. Use Certified Specialty Coders

General medical billers often lack the specialty knowledge to code complex procedures accurately. At RCMAXIS, every account is assigned coders with specialty-specific certifications who understand the nuances of each practice type we serve.

4. Quarterly Comparative Analysis

Compare your coding distribution against CMS utilization benchmarks for your specialty and region. If your Level 4 visit rate is significantly below the specialty average, it warrants investigation. Our analytics and reporting service includes automated code-level benchmarking.

The Bottom Line

Under-coding is not playing it safe. It is leaving money on the table while creating inaccurate medical records. The solution is not to upcode, it is to code accurately, every time, supported by proper documentation. For most specialty practices, accurate coding increases revenue by 15-25% without changing a single clinical workflow.

Ready to find out how much your practice is leaving behind? Request a free coding audit.