Modifier for Maximum DME Units

Hi,

I recently had a gotten denied on an Oral Appliance claim for a patient. The denial read "maximum units fulfilled on policy'. When i spoke to the carrier, they advised to attach the correct modifier to the claim and it should pay.

Do you have any idea what modifier this would be? I have searched up and down to uncover the correct modifier. We are billing for a Sleep specialist who's pt needs an oral appliance because PAP therapy is not working.

Thank you

Susan Gill