Pulmonology 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 not much is “automatic” when it comes to leveling an encounter.

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

However, a condition that is undiagnosed as of 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., PND, bronchitis, pneumonia) should be documented, and this would likely be accompanied by additional work-up (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 will sometimes rise 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 be sure to include these considerations within the documentation for the E/M service.