Subsequent Inpatient Visits

I was recently informed by a fellow coder that in order to bill for a level 3 subsequent hospital visit, there has to be at least 4 diagnoses. This coder stated that if less than four diagnoses were listed in the documentation, even if all the documentation supported a level 3, then only a level 2 could be billed.
Does anyone know if this is correct?

re: Subsequent Inpatient Visits

E/M codes are defined and determined on the level of service for reporting purposes not diagnosis codes. I have never heard of a requirement on how many diagnosis codes you should use. I would like to see in the rules and/or guidelines where this is stated.

re: Subsequent Inpatient Visits

We should not pick the level based on diagnosis based on the service rendered we have to finalize the CPT level.