Does an E/M service require an exam? It depends on the category of service.

Established patients and subsequent hospital visits require two out of three of the key components, history, exam and medical decision making.  Any two components at the level of documentation required determines the level of service.  The exam does not need to be one of them.  Many established patient visits meet the criteria in history and medical decision making.

Other categories of service, for example, new patients, consults and initial hospital services, require three of the three components to be at or exceed the level of documentation required.  This means, in effect, that the lowest component selects the code.  A new patient that has no exam is not reportable unless it meets the criteria for an E/M service based on time.  (There is an article in Codapedia about using time to select a code.)  An exam that includes vital signs or general appearance allows the service to be billed at the lowest level.

What should a practice do if there is no exam, and time is not a determining factor in selecting the code?  Use the unlisted E/M code, 99499. 

The CPT book defines the level of history, exam and MDM for each level of E/M code, and whether it requires two of three, or all three components.  The Documentation Guidelines describe what makes up each level of history, exam and MDM.