Oncology & Hematology Coding Alert

Question: Does an undiagnosed new problem with uncertain diagnosis automatically mean a moderate level of problem complexity?

Minnesota Subscriber

Answer: The answer to this question really depends on the situation and the documentation, but there is really not much that is “automatic” when it comes to leveling an encounter.

The confusion revolves around the different ways ICD-10-CM and CPT^® operate in regard to uncertain diagnoses. With ICD-10-CM, you are bound by the guideline IV.H for reporting diagnosis codes, which tells you not to code a condition documented “as ‘probable,’ ‘suspected,’ ‘questionable,’ ‘rule out,’ ‘compatible with,’ ‘consistent with,’ or ‘working diagnosis,’ or other similar terms indicating uncertainty.”

However, an undiagnosed condition on the date of service (DOS) has to factor into the medical decision making (MDM) calculation for the evaluation and management (E/M) service. For example, a cough, nausea, and fatigue could just be a case of allergies, and the provider may treat it as such. If a provider has a suspicion that the condition could be something worse, the differential diagnosis (e.g., paroxysmal nocturnal dyspnea (PND), bronchitis, pneumonia) should be documented, and this would likely be accompanied by additional workup (e.g., pulmonary function tests, chest X-rays, complete blood count (CBC), complete metabolic panel (CMP), etc.). This shows the complexity of the encounter, which adds to support and sometimes increases complexity to the moderate level of MDM for such conditions.

Remember, CPT^® began to provide a definition of an undiagnosed new problem with uncertain prognosis in 2021, stating it is “A problem in the differential diagnosis that represents a condition likely to result in a high risk of morbidity without treatment. An example may be a lump in the breast.”

In other words, you won’t select a probable or rule-out ICD-10-CM code for the diagnosis portion of the encounter, but you should consider the information and the resulting diagnostic treatment decisions the provider lists in the documentation for the E/M service.