I’m aware that modifiers are used to indicate a procedure has been altered, etc., but how else are they used?

Modifiers may be used to indicate to the recipient of a report that:

• A service or procedure has both a professional and technical component.
• A service or procedure was performed by more than one physician and/or in and/or in more than one location.
• A service or procedure has been increased or reduced.
• Only part of a service was performed.
• An adjunctive service was performed.
• A bilateral procedure was performed.
• A service or procedure was provided more than once.
• Unusual events occurred.