Introduction
Insurance denials are a frequent and frustrating part of running a general surgery practice. Due to the complexity of procedures and the strict guidelines set by payers, claims are often rejected for reasons ranging from simple coding mistakes to missing documentation or lack of pre-authorization. Understanding the most common denial codes in general surgery can help practices address the root causes and reduce payment delays. In this post, we’ll break down the top 10 denial reasons specific to general surgery, explain why they occur, and provide practical tips to help prevent them from disrupting your revenue cycle.
Common Denial Codes in General Surgery
| Denial Code | Description |
|---|---|
CO-50 | Medical necessity not supported |
CO-11 | Diagnosis and procedure code mismatch |
CO-18 | Duplicate claim/service |
CO-16 | Claim lacks necessary information |
CO-22 | Coordination of benefits (COB) |
CO-96 | Non-covered charges |
CO-197 | Preauthorization required |
CO-29 | Late filing |
CO-59 | Global surgery package error |
CO-45 | Charges exceed the fee schedule |
Detailed Analysis of Top 10 Denials
1. Denial Code: CO-50
Description: Medical Necessity Not Supported
Medical necessity denials happen when the insurer decides that the surgery was not needed based on the documentation submitted. Payers expect clear evidence that surgery was the appropriate course of treatment, especially if other, less invasive options could have been tried. This type of denial is common for procedures like bariatric surgery, hernia repair, or some endoscopic operations, where strict medical necessity guidelines often apply.
Prevention:
- Document all non-surgical treatments attempted before surgery
- Include exam findings that support the need for the procedure
- Refer to clinical guidelines that justify the surgical approach
- Explain how the condition affects the patient’s daily life
- Include notes from any specialists supporting the decision to operate
- Clearly state the reasons for surgery in the operative report
- Use a checklist before surgery to confirm all medical necessity documentation is complete
- Consider templates to help cover the required details in your notes
2. Denial Code: CO-11
Description: Diagnosis and Procedure Code Mismatch
This denial occurs when the diagnosis code submitted does not adequately support or justify the surgical procedure performed. Insurers expect a logical connection between the patient’s diagnosis and the chosen intervention. In general surgery, this often happens with complex cases involving multiple conditions or when the primary reason for surgery is not clearly coded as the principal diagnosis.
Prevention:
- Create procedure-specific diagnosis code mapping tools for common surgeries
- Review the medical record holistically to identify all relevant diagnoses
- Sequence diagnosis codes appropriately with the principal diagnosis listed first
- Document comorbidities that may impact surgical decision-making
- Implement an internal audit process to verify diagnosis-procedure alignment
- Consider specialized coding education for complex general surgery procedures
- Use specificity in diagnosis coding rather than general or unspecified codes
3. Denial Code: CO-18
Description: Duplicate Claim Submission
Duplicate claim denials occur when the same service is billed multiple times, whether inadvertently or due to resubmission without proper modification. Anesthesiology practices frequently encounter this denial when tracking claims across multiple locations and payers, when resubmitting corrected claims, or when facility and professional components are billed separately. The high volume of cases managed by anesthesiology groups increases the risk of tracking errors that lead to duplicate submissions.
Prevention:
- Implement claim tracking systems to monitor submission status
- Create clear protocols for claim correction versus resubmission
- Establish communication channels between facility and professional billing teams
- Use practice management software with duplicate detection capabilities
- Review all claims rejected as duplicates to understand root causes
- Conduct regular audits of billing processes to identify potential duplicate submission patterns
4. Denial Code: CO-16
Description: Claim Lacks Necessary Information
This denial occurs when essential information is missing from the claim submission, preventing proper processing. For general surgery practices, these information gaps may include incomplete patient demographics, missing or invalid insurance information, insufficient procedure details, or incomplete documentation of implants or high-cost supplies. Surgical claims often require more detailed information than other specialties due to the complexity of procedures and associated costs.
Prevention:
- Create comprehensive pre-registration processes to capture all required patient information
- Implement claim scrubbing software to identify missing elements before submission
- Develop procedure-specific checklists for documentation requirements
- Regularly update provider enrollment information with all payers
- Train staff on the specific information requirements for surgical claims
5. Denial Code: CO-22
Description: Coordination of Benefits (COB)
COB denials arise when there is confusion about which insurer should be the primary payer when a patient has multiple insurance plans. For surgical procedures with significant costs, insurers are particularly vigilant about ensuring they are not paying as primary when they should be secondary. These denials can significantly delay payment as claims bounce between insurers.
Prevention:
- Verify primary and secondary coverage during pre-registration
- Document COB information clearly in the patient record
- Obtain copies of all insurance cards and verify coverage with each carrier
- Ask specific questions about other potential coverage (spouse’s insurance, Medicare, etc.)
- Implement a yearly insurance verification process for all active patients
- Create a dedicated process for handling patients with dual coverage
6. Denial Code: CO-96
Description: Non-covered Charges
Non-covered charges denials occur when procedures or services provided are excluded from the patient’s insurance benefits. In general surgery, this often applies to cosmetic components of otherwise medically necessary procedures, experimental techniques, or certain bariatric procedures with specific coverage criteria. These denials can be particularly challenging as they often result in patient responsibility for payment.
Prevention:
- Verify benefits specifically for planned procedures prior to surgery
- Understand payer-specific coverage policies for common procedures
- Provide patients with advance beneficiary notices (ABNs) when coverage is questionable
- Separate billable components of procedures from non-covered portions when appropriate
- Stay informed about new coverage determinations and policy updates
7. Denial Code: CO-197
Description: Preauthorization Required
This denial occurs when a required preauthorization was not obtained before performing surgery. Almost all non-emergency surgical procedures require prior authorization from insurance companies, and failing to secure this approval is one of the most common and costly denial reasons in general surgery practices. Each payer has specific requirements regarding what information must be submitted and how far in advance authorization must be obtained.
Prevention:
- Create a centralized preauthorization process with clear accountability
- Develop a comprehensive list of which procedures require authorization by payer
- Implement an authorization tracking system with alerts for pending and approved cases
- Document authorization numbers in both the scheduling and billing systems
- Verify authorization status during pre-operative calls
- Create emergency protocols for urgent cases when standard authorization is not possible
8. Denial Code: CO-29
Description: Late Filing
Late filing denials occur when claims are submitted after the payer’s allowed timeframe, which varies from 30 days to one year depending on the payer. For general surgery practices dealing with complex cases and multiple payers, timely submission can be challenging, especially when additional information or documentation is required before claim submission.
Prevention:
- Create a filing deadline calendar organized by payer
- Establish a standard claim submission schedule (daily or weekly)
- Implement electronic claims submission for faster processing
- Track claim status regularly to identify and address issues promptly
- Prioritize high-dollar surgical claims for expedited processing
- Create exception reports for claims approaching filing deadlines
9. Denial Code: CO-59
Description: Global Surgery Package Error
Global surgery package denials occur when services included in the global surgical package are billed separately or when modifiers indicating services outside the global period are used incorrectly. This is particularly challenging in general surgery, where the global periods (typically 0, 10, or 90 days) vary by procedure, and multiple procedures may be performed during the same operative session.
Prevention:
- Maintain current knowledge of global period assignments for common procedures
- Create procedure-specific guidelines for global period management
- Properly document and code for complications or unrelated services during the global period
- Use appropriate modifiers (-58, -78, -79) correctly when billing for related or unrelated procedures
- Train surgeons on documentation requirements for services outside the global package
10. Denial Code: CO-45
Description: Charges Exceed the Fee Schedule
This denial indicates that the amount billed exceeds the maximum allowable charge according to the payer’s fee schedule. While this typically results in a reduction to the contracted rate rather than a complete denial, it can impact expected reimbursement and create reconciliation issues. For expensive surgical procedures, understanding payer-specific allowable amounts is crucial for accurate financial forecasting.
Prevention:
- Maintain updated fee schedules for all contracted payers
- Regularly review and update charge masters based on payer contracts
- Monitor reimbursement patterns to identify discrepancies between expected and actual payments
- Develop financial models that accurately predict reimbursement for common procedures
- Understand carve-outs or exceptions in payer contracts that might apply to certain surgeries
- Implement contract management software to track fee schedule changes
Conclusion
For general surgery practices, proactively addressing these top ten denial reasons can significantly improve revenue cycle performance and financial stability. By implementing targeted prevention strategies for each denial type, practices can increase clean claim rates, reduce administrative costs associated with rework, and improve cash flow. The key to success lies in creating robust pre-service processes, maintaining detailed clinical documentation, investing in ongoing education for both clinical and billing staff, and establishing strong communication channels between departments.