Why Is Modifier 25 One of the OIG’s Biggest Audit Targets?

Medical Answer

Few coding topics create more confusion, denials, and audit risk than Modifier 25. The modifier allows providers to bill a significant, separately identifiable Evaluation and Management (E/M) service on the same day as a procedure.

Most physician practices use it appropriately.  The problem is that many providers, coders, and billers interpret the requirements differently. One provider may believe every procedure visit deserves a separate office visit. Another may avoid Modifier 25 entirely because they’re worried about audits. Both approaches can create problems.

It can significantly increase reimbursement when applied correctly—and overpayments when applied incorrectly. The challenge is finding the balance between proper reimbursement and compliance. That’s exactly why the OIG continues to review Modifier 25 usage.

When documentation does not clearly support the separate E/M service, payers and auditors may view the claim as improperly billed. OIG audits have identified substantial overpayments related to Modifier 25 usage across multiple specialties.

Let’s Take a Closer Look – What Is Modifier 25?

Modifier 25 is appended to an E/M service when a provider performs a: Significant, separately identifiable Evaluation and Management service on the same day as a procedure or other service.

The key words are: Significant and Separately Identifiable. Those two concepts determine whether Modifier 25 is appropriate.

Why Does the OIG Focus on Modifier 25?

Simply put: Modifier 25 can increase reimbursement. Because of that, government agencies and payers want to ensure it is being used correctly.

The OIG has conducted multiple reviews involving Modifier 25 and identified significant error rates and estimated overpayments. Several audits focused on specialties where Modifier 25 is commonly reported.

The concern isn’t that providers perform procedures and evaluations on the same day. The concern is whether the documentation truly supports both services.

Which Specialties Have Been Reviewed?

Experts have highlighted OIG reviews involving:

• Dermatology
• Ophthalmology
• Podiatry

These audits found that many claims lacked sufficient documentation to support the separate E/M service billed with Modifier 25. That doesn’t mean these specialties are doing anything wrong. It means they frequently perform procedures and therefore frequently use Modifier 25.

What Documentation Should Support Modifier 25?

The documentation should clearly show:

• Why the patient presented
• What evaluation occurred
• Medical decision making
• Why the E/M service was separate from the procedure
• Medical necessity for both services

An auditor should be able to easily identify the work performed beyond what was required for the procedure itself.

Common Documentation Mistakes

One of the most common mistakes occurs when the note focuses entirely on the procedure. The provider documents:

• The injection
• The lesion removal
• The procedure details

But fails to document the separate evaluation that occurred beforehand. When that happens, auditors may conclude that the E/M service was already included in the procedure and should not have been billed separately.

Medical Necessity Still Matters

Even if the provider documents a separate evaluation, medical necessity must still support it. Auditors often ask: “Would this E/M service have been necessary if the procedure had never occurred?”

If the answer is yes and the documentation supports that work, Modifier 25 may be appropriate. If the answer is no, additional review may be needed.

Real Practice Example

A dermatology practice noticed an increase in payer requests for records involving Modifier 25 claims. Leadership initially assumed the issue was payer-specific. However, an internal audit revealed that providers documented procedures thoroughly but varied significantly in how they documented the separate E/M service.

Some notes clearly described the patient’s concerns, evaluation, and decision making. Others focused almost exclusively on the procedure.

The practice implemented provider education and created documentation examples illustrating when Modifier 25 was appropriate. Within several months, documentation consistency improved and record requests became easier to manage.

The issue wasn’t the modifier. It was the documentation supporting it.

Does frequent Modifier 25 use automatically create audit risk?

Not necessarily. Some specialties appropriately use Modifier 25 more often than others.

The concern isn’t frequency alone. The concern is whether the documentation consistently supports the services billed. One of the biggest mistakes is treating Modifier 25 as a billing decision rather than a documentation decision.

The modifier doesn’t create the separate service. The documentation does. When providers focus on documenting the separate evaluation first, coding decisions become much easier. Practices that can explain and support their usage patterns are generally in a stronger position during reviews.

Protect Your Practice Before an Auditor Reviews Your Claims

✅ Pull 25 recent Modifier 25 claims.

✅ Review documentation supporting the E/M service.

✅ Compare provider usage patterns.

✅ Identify documentation inconsistencies.

✅ Provide focused education where needed.

✅ Audit Modifier 25 claims quarterly.

Remember: The goal isn’t to reduce Modifier 25 usage. The goal is to ensure it’s supported.

Bottom Line

Modifier 25 continues to attract OIG attention because it directly affects reimbursement and has historically been associated with high error rates. The key to compliance is not avoiding Modifier 25—it’s ensuring that documentation clearly supports a significant, separately identifiable E/M service. Practices that regularly audit Modifier 25 usage, educate providers, and strengthen documentation are often best positioned to reduce audit risk and protect reimbursement.

Key Takeaways

• Modifier 25 remains a significant OIG audit target.
• Documentation—not the modifier itself—determines compliance.
• The E/M service must be significant and separately identifiable.
• High error rates have been found in multiple specialties.
• Internal audits can help identify inappropriate usage.
• Medical necessity should support both services.
• Provider education remains critical.

Stay Ahead of Modifier 25 Audit Risks Modifier 25 remains one of the most frequently reviewed coding issues in healthcare. Healthcare Training Leader’s All-Access Training Pass provides ongoing education on Modifier 25, E/M coding, documentation, medical necessity, payer audits, coding compliance, and OIG priorities. Instead of waiting until denials or audits occur, your providers, coders, and billers can stay current on documentation expectations and coding requirements throughout the year.