1. C: The modifier -25 belongs on the office visit. Also, because the decision to give the injection was not determined until after the rheumatologist examined the patient to perform an injection, both the office visit and the injection are allowed. The modifier -LT is used just to identify on which knee the injection was performed. Some carriers require this, and some do not; check with your carrier for their billing requirements.
2. C: An office visit should not be billed in this example because the physician already knew why the patient was coming in, and there was no separate and significant reason for the additional office visit.
3. B: There can only be one initial code in the drug administration family. If there is a need to code for an additional drug administration procedure, the subsequent code should be used. If saline is used to flush out the drug, the administration for normal saline can be coded with a modifier -59.