In today’s increasingly complex reimbursement environment, compliant documentation is no longer just a best practice; it is a business imperative. While most O&P professionals understand the importance of documentation, noncompliance remains one of the leading causes of claim denials and post-payment recoupments.
The most recent 2025 Comprehensive Error Rate Testing (CERT) data reinforces this reality, identifying missing and insufficient documentation as a primary driver of improper payments across the DMEPOS landscape. When isolating O&P-related product categories, the trend becomes even more pronounced: Documentation failures significantly outpace issues related to medical necessity or coding accuracy.
O&P Error Rates Highlight a Persistent Documentation Challenge
A closer look at CERT findings for key O&P policy groups in the chart below underscores where suppliers remain most vulnerable.
Across all categories, documentation-related errors account for a majority of improper payments, highlighting an area where O&P practices can make meaningful improvements.
Understanding the Most Common Documentation Errors
No Documentation
No documentation errors occur when suppliers fail to submit any documentation during a post-payment CERT review or submit it after the deadline. CERT request letters are mailed to the address on file in the Provider Enrollment, Chain, and Ownership System (PECOS). Inaccurate or outdated PECOS information does not excuse lack of response, making routine enrollment maintenance essential.
Suppliers are given 45 days to respond to requests for documentation; failure to do so results in recoupment of the reviewed claim. Even when a supplier anticipates an unfavorable outcome, responding to documentation requests is strongly recommended. Nonresponse reflects poorly on the supplier and may elevate scrutiny in future audits.
Insufficient Documentation
Insufficient documentation is a broader and more nuanced category. It may involve missing required elements (such as proof of delivery) or documentation that lacks the clinical detail necessary to justify the provided device.
Common insufficiencies include:
- Incomplete physician records
- Clinical notes that fail to clearly support coverage criteria
- Missing supplier-generated documentation
- Limited explanation of functional deficits or expected benefit
To support providers, CGS and Noridian, the DME MACs, have published documentation checklists by policy group. These tools outline required documentation elements and serve as an excellent presubmission reference to reduce avoidable errors.
Medical Necessity
Medical necessity errors occur when the referring physician’s records do not adequately support the coverage criteria outlined in the applicable Local Coverage Determination (LCD) or policy.
While physician documentation is not always required prior to delivery (unless prior authorization applies), proactively obtaining and reviewing these records can significantly reduce post-payment audit risk. Unlike missing paperwork, medical necessity deficiencies are difficult, if not impossible, to correct after a claim has been processed. Practices are encouraged to implement internal workflows that include review of physician documentation prior to delivery whenever feasible. Addressing medical necessity upfront protects both patients and practice revenue.
Incorrect Coding
Although often less prevalent in CERT data, incorrect coding errors remain important. These errors may include incorrect HCPCS codes, inappropriate or missing modifiers, and unsupported add-on codes.
A commonly overlooked factor is whether the clinical documentation supports every code billed. Clinical notes must not only justify the device but also explain why each billed base and add-on code is medically appropriate. Unsupported codes, regardless of intent, can result in adverse audit findings.
Why CERT Data Matters Beyond Individual Claims
CERT findings have implications that extend well beyond individual practices. Improper payment data generated from CERT reviews is published annually in the Health and Human Services Agency Financial Report, influencing Medicare program integrity initiatives across both traditional Medicare and Medicare Advantage plans.
Historically, policy groups demonstrating high CERT error rates have been followed by increased targeted medical reviews, new audit initiatives from the DME MACs, and new Recovery Audit Contractor issues. For this reason, DME MACs place particular emphasis on CERT education and outreach, viewing it as an early indicator of future audit focus.
Using CERT Data to Strengthen Internal Compliance
Rather than viewing CERT results as purely punitive, O&P suppliers can use this data strategically. Incorporating CERT insights into compliance planning allows practices to identify high-risk documentation gaps, prioritize staff education and training, and anticipate upcoming audit activity. Implementing annual internal compliance reviews, with a focus on documentation completeness, medical necessity alignment, and coding support, can substantially reduce denials and recoupments while improving overall reimbursement performance.
Lesleigh Sisson, CFo, CFm, and Curt Bertram, CPO, are part of the leadership team at O&P Insight. Sisson and Bertram have a combined 64 years of experience in O&P administration, clinical services, and operational management. You can contact them at lesleigh@oandpinsight.com or curt@oandpinsight.com. Michelle Wullstein, CPCO, has been in the Medicare profession for over 18 years and is an AAPC-certified professional compliance officer and provides O&P specific medical policy, billing, documentation, and HIPAA compliance support to internal teams and clients. While every attempt has been made to ensure accuracy, The O&P EDGE is not responsible for errors.
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