Denial Watchlist: CPT Codes That Often Trigger Claims Denials

Healthcare revenue teams deal with claims denials daily, but not all CPT codes are equal when it comes to rejection rates. While some codes are high-volume, others are complex and associated with high-dollar claims. By understanding which CPT codes frequently trigger denials and why, revenue cycle managers (RCM), medical billers, coders, and clinical teams can proactively address issues, reduce rejections, and speed up appeals.

In this guide, we’ll highlight the top CPT codes that trigger denials, discuss the common reasons for those denials, and offer practical, actionable steps to prevent them. You’ll also find audit checklists, common search queries, and tips for reducing your overall denial rate.

Why Certain CPTs Deny More Often

Denials are not random. Certain CPT codes deny more frequently due to specific issues such as documentation errors, prior authorization problems, or NCCI edits. By understanding the root causes, you can implement effective preventive measures. Below are the most common reasons why CPT codes face denials:

Documentation Issues

One of the biggest reasons for denials is inadequate documentation. Without proper documentation to support the billed code, claims are often rejected or downcoded. This can include missing history, insufficient exam details, or lack of justification for medical decision-making (MDM).

Prior Authorization Failures

Many codes require prior authorization from the payer before services are rendered. If this step is missed or delayed, claims will be denied. It's essential to verify whether prior authorization is required for certain services before submission.

NCCI Edits and Modifier Issues

The National Correct Coding Initiative (NCCI) edits identify when codes are incorrectly paired or bundled. For example, if two services are billed together that shouldn’t be, the payer will reject one or both services. Similarly, incorrect use of modifiers (e.g., modifier 59) can lead to denials, especially when not applied correctly for separate or distinct services.

Administrative Errors

Even simple administrative mistakes—such as missing signatures, incorrect dates, or invalid codes—can result in denials. It's important to double-check the accuracy of every detail before submitting claims.

Key Code Groups to Monitor

There are several CPT code families that are particularly prone to denials. These codes are high-risk due to their volume or complexity. Let’s break down these key code groups and the common reasons they trigger denials.

Evaluation & Management (E/M) — 99202–99215

Common Examples: 99213, 99214, 99203

Why They Deny: E/M codes, particularly 99214, often face denials due to insufficient documentation. Denial reasons include missing history, exam details, or inadequate justification of the level of service. Sometimes, the documentation doesn't align with the time or medical decision-making (MDM) required for higher levels.

Quick Fixes:

• Use focused documentation templates to capture all necessary details, such as a clear chief complaint and HPI (History of Present Illness).
• Require clinicians to document time or MDM justifications for higher-level E/M codes.
• Perform a pre-bill audit for higher-cost or frequently denied E/M codes to ensure the documentation aligns with the billed level.

Example:
If you're regularly encountering denials for 99214, ensure that every chart includes a well-documented problem list, assessment, and plan. These elements should clearly justify the complexity of the visit.

Laboratory & Panel Codes — 80047–80076, Common Panels

Common Examples: 80050, 80053, 84153

Why They Deny: Lab codes often face denials due to missing orders, CLIA certification errors, or diagnosis mismatches. It's essential to match the correct diagnosis with the lab panels ordered, as well as ensure that the appropriate certification information is on file.

Quick Fixes:

• Require scanned lab orders to be included with every claim.
• Validate that the ordering provider's CLIA certification is active and valid.
• Ensure that lab codes are not improperly bundled with unrelated tests, leading to denials.

Example:
For lab panels like 80050 (General Health Panel), confirm that the provider's diagnosis aligns with the tests ordered. Missing or mismatched codes are a common denial reason.

Imaging & Radiology — (70000–79999)

Common Examples: 73721 (Knee MRI), 70450 (CT Head), 71260 (CT Chest)

Why They Deny: Imaging and radiology services are frequently denied for missing prior authorization or incorrect modifier usage. Additionally, these services often face denials due to NCCI bundling errors, especially when multiple services are billed together.

Quick Fixes:

• Implement front-end prior authorization checks for all high-cost imaging services to ensure that authorizations are in place before the service is provided.
• Use templates for clinical indications that ensure all required details for authorization are included.
• Train billing teams on modifier use to avoid improper claims and ensure claims for distinct services are not bundled together incorrectly.

Therapy Codes — PT, OT, Speech (97110, 97112, 97140)

Why They Deny: Therapy codes are frequently denied due to missing certifications, insufficient progress documentation, or frequency limit violations. Payers often require specific documentation of progress to continue therapy services.

Quick Fixes:

• Develop progress-note templates for therapists to standardize documentation.
• Keep track of recertification schedules and ensure that the appropriate documentation is submitted before therapy sessions exceed allowable limits.
• Make sure that any frequency limits (such as the maximum number of therapy sessions covered by the payer) are respected.

Infusion/Injection & Oncology (96360–96379 + J-codes)

Why They Deny: Infusion and oncology codes often face denials due to drug-specific payer rules, missing authorizations, or incorrect J-code mapping. The relationship between CPT codes and J-codes must be accurately reflected to avoid rejections.

Quick Fixes:

• Develop drug-specific payer playbooks that detail the specific authorization requirements for each medication.
• Ensure that NDC/J-code mappings are verified before claim submission, and that payer-specific guidelines are followed.

Modifiers & Global Periods (25, 59, 76, Global Surgery Denials)

Why They Deny: Improper use of modifiers (such as 25, 59, and 76) can lead to denials. Additionally, mistakes during global period billing can trigger rejections, especially when billing for procedures related to surgery during the global period.

Quick Fixes:

• Use automated NCCI checks to flag incorrect modifier use.
• Create a modifier decision tree for billing teams to reference when unsure which modifier to apply.

Practical Denial-Management Playbook

Now that we’ve covered the major CPT groups prone to denials, it’s time to implement a strategy that reduces rejections and speeds up appeals.

Step 1: Pull Denial Reports

Start by pulling denial reports by CPT code and dollar amount. Prioritize high-dollar and high-volume codes for deeper analysis and faster intervention. This helps your team focus on the areas with the highest potential for improvement.

Step 2: Create Code-Specific Audit Templates

Develop audit templates that highlight the key documentation requirements for each high-risk CPT. For example, for a common E/M code like 99214, create a checklist that includes:

• Visit date and provider signature.
• Clear chief complaint and HPI.
• Proper documentation of MDM or time spent.

Step 3: Implement Front-End Edits

Enforce front-end edits that require lab orders, prior authorization checks, and CLIA validation before claims are submitted. These preventive measures can stop denials before they even happen.

Step 4: Standardize Appeal Templates

Create appeal templates that can be customized for each type of denial reason. Include standardized language for common issues like medical necessity, missing prior authorization, and bundling errors. This will save time when dealing with repeated denial reasons.

Step 5: Develop Payer Playbooks

Create payer-specific playbooks for your top five payers. These playbooks should outline what each payer accepts, their turnaround times, and the best contact pathways for escalating claims.

Step 6: Measure and Improve

Track your denial rate by CPT, your appeal success percentage, and the days in A/R for claims. This data can help you fine-tune your process and identify areas for further improvement.

Sample Audit Checklist: 99214

For your reference, here’s a quick audit checklist for reviewing 99214 claims:

• Confirm visit date and provider signature.
• Ensure chief complaint and HPI support the complexity.
• Validate exam or MDM is sufficient for the level billed.
• Check for a problem list and assessment with clear plan.
• Ensure relevant tests/orders are included with justification.
• If billed with a procedure, verify modifier 25 is used.

If denied, always refer to the denial code (e.g., CO-50, CO-97) and attach supporting documentation during the appeal.

Conclusion + Next Steps

By focusing on high-risk CPT codes and understanding the reasons behind common denials, healthcare teams can take proactive steps to reduce rejections and speed up the claims process. Use the strategies in this guide to improve documentation, streamline your front-end processes, and standardize your appeal methods.

Ready to reduce your denial rate? Download our Denial Audit Checklist (PDF) today!