Maybe ...
If the reason for the visit was to receive the injection (i.e. it was previously scheduled) then, NO, you cannot charge for the E/M (unless some completely diffferent issue was evaluated).
However, you state the last injection was 5 months previous. Was the patient released from treatment at that time? Was this a new problem or even a recurrence of a previous probllem?
If at the last visit the physician had no intention of seeing the patient again for the problem, then it would be reasonable for him to have to evaluate the injury/disease process to determine a course of treatment (which, in this case, would be the injection). If that is the case, you might be able to use the -25 modifier. It will all depend on the documentation (what else?).
Hope that helps.
F Tessa Bartels, CPC, CEMC