Probable Diagnoses, Missing Date, and a Post-Audit Addendum
A RADV audit selects a 77-year-old male member. The submitted diagnoses include Parkinson's disease (G20) and multiple sclerosis (G35). The only support is a progress note typed by a medical assistant and signed by the physician without a date. The note says 'probable Parkinson's disease' and 'rule out MS.' Two months after the audit request, an addendum appears stating 'Parkinson's disease confirmed' and 'MS ruled out.' The addendum is dated the day it was created and signed. A billing encounter form also lists G20 and G35, but the form has no clinical details.
1. Which submitted diagnoses are supported, and why?
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Neither G20 nor G35 is supported as submitted. 'Probable Parkinson's disease' and 'rule out MS' are uncertain diagnoses and cannot be coded. The billing form alone is not clinical documentation.
The addendum could support G20 only if it is a valid late entry, but it was created after the audit request, so auditors will scrutinize it. G35 is explicitly ruled out. The original note supports no definitive HCC.
2. What are the concerns with the undated signature and the post-audit addendum?
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An undated physician signature may require a signature attestation. A late addendum is permissible only if it is clearly dated, timed, and explains why it is late; it cannot be backdated.
An addendum created after RADV notification that confirms a diagnosis is a red flag for retroactive documentation. The auditor may reject it unless there is contemporaneous evidence. Compliance should review the timing and consider whether the addendum is credible.
3. How is the RADV error rate calculated, and what is the likely consequence for this member?
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RADV validates each submitted HCC against the record. Unsupported HCCs are errors. The error rate is the number of unsupported HCCs divided by the HCCs reviewed, or a payment-weighted error rate.
For this member, both G20 and G35 would likely be removed if the addendum is rejected, and the risk score would be recalculated. If the plan's sample error rate exceeds the threshold, CMS may extrapolate the overpayment and require a corrective action plan.