# Modifier 21



## cynthiar (Dec 27, 2007)

I received a publication that stated the modifier 21 could only be used with the highest level E/M services, such as 99205 or 99215.  Can this code not be used with all E/M services at the highest level?


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## thompsonsyl (Dec 27, 2007)

Hi,

I was taught the same thing regarding use of modifier 21 - that it can only be used when "the E/M service is prolonged or the service is otherwise greater than that usually required for the highest level of E/M service within a given category".


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