medicare reimbursement

I have been getting denials for CPT® 99223 when billed with a procedure, example 36556.
I bill the 99223 with modifier 57, decision for sx, and 36556. EOB will come back with procedure paid but not the consult. EOB states payment is included in another payment/allowance already adjudicated.

What does that mean? and am I billing incorrectly?

Thanks

re: medicare reimbursement

Use a 25 modifier on the 99223 instead of the 57.