What modifier would I use?

[shelbylmk]

I have a provider that is going to be having shoulder surgery and will not be working for a minimum of 2 months, possibly 3 months. He is wanting to have a previous business partner come in to see patients for him.

Is there a specific modifier I would use on the claim, like AM? Do I bill the insurance companies with the previous business partner on the claim since I still have his info in our system?

How would you handle the situation?

Any advice would be great. Please and thank you