Why do some diagnoses appear on the MAO-004 reports showing as accepted and allowed, but do not appear on the 2019 Initial payment MOR?

There are a number of reasons why the Hierarchical Condition Category (HCC) for a diagnosis reported as accepted and allowed on the MAO-004 report would not appear on the Initial payment Model Output Report (MOR). A diagnosis code that is added and allowed is considered for risk adjustment and will appear on the MOR. While the MAO-004 reports all diagnosis codes submitted on accepted encounters not all diagnosis codes reported map to a payment HCC. In addition, it is possible that there is a diagnosis that maps to a payment HCC that is higher in a hierarchy and thus a lower severity HCC in the same hierarchy would not be included in the risk score for payment. The MOR reports HCCs after the hierarchies are applied, therefore the lower severity HCC that was excluded for payment will not be reported on the MOR. Please also ensure that the diagnosis was submitted on an encounter with dates of service within the submission window for the [payment year’s] Initial and was not deleted by a subsequent replacement or chart review delete.