Ambulatory Surgical Center (ASC) Billing Codes

Ambulatory Surgical Centers (ASCs) bill Medicare using HCPCS and CPT codes, but they receive facility fees under the ASC Payment System — a separate schedule from the Physician Fee Schedule or OPPS. The ASC fee schedule sets the maximum allowed facility amount for procedures performed in a Medicare-certified ASC. The surgeon bills separately under the Physician Fee Schedule for the professional component.

Not every CPT or HCPCS procedure is covered in an ASC. CMS maintains a list of ASC-covered procedures, and items not on the list are not separately payable in the ASC setting. Certain device-intensive procedures are paid at a higher rate to account for the cost of implants. For some procedures, the ASC rate is a percentage of the OPPS rate.

HCPCS Level II codes appear on ASC claims primarily for supplies, drugs, and equipment used during the procedure. These may be packaged into the facility payment (not separately reimbursed) or separately payable depending on whether CMS has assigned a packaged status indicator or a separate payment indicator to the code.

ASCs must bill on the UB-04 form (or its electronic equivalent, the 837I claim transaction), while the operating physician bills on the CMS-1500 (837P). Getting the billing setting correct is essential — filing a procedure with the wrong setting can result in denials or incorrect payment. Review ASC rates by code to confirm payment amounts before scheduling procedures.