A modifier is a code that provides the means by which the reporting physician can indicate that a service or procedure that has been performed has been altered by some specific circumstance but has not changed in its definition or code.

What are the modifier codes?

Code modifiers are codes that supply further information about a CPT or HCPCS code, such as if the procedure was more complicated than normal or performed under unusual circumstances.

What is meant by modifier in medical billing?

According to the AMA and the CMS, a modifier provides the means to report or indicate that a service or procedure has been performed and altered by some specific circumstance but not changed in definition.