Saw this on the aapc site:
Modifier SA is for a nurse practitioner rendering service in collaboration with a physician.
Some carriers will recognize these modifiers and some will not. Those that will not may deny the claims because the modifier is not one they recognize and that makes the claim not a "clean claim".
I would query your biggest carriers first, and/or those you have ties with, and ask them if they recognize the SA modifier (it doesn't seem the YR applies to this). If so, how do they want modifier SA utilized?