Ambulatory Surgery Center (ASC) facility services — Modifier SG and Place of Service 24
This reimbursement/payment policy defines when Premera recognizes ASC facility services billed on CMS-1500 or 837P claims using Modifier SG and Place of Service code 24 and how to submit the ASC NPI; it applies to Premera Blue Cross and affiliated lines of business.
Clarified the data elements that should be submitted to identify ASC facility services (how to enter the ASC's NPI on claims).
Changed the policy title and reordered bullets for Modifier SG and Place of Service code 24.
ASC Facility Service Recognition & Submission
ASC recognition and claim submission
Coverage recognition and claim submission requirements for ASC facility services billed on CMS-1500 or 837P.
Modifier requirement
- Append Modifier SG to any facility service rendered by an ASC to identify it as an ASC service.
- Do not append Modifier SG to physician or other qualified health care professional services.
Place of service
- Use Place of Service code 24 for the submission of any service rendered in an ASC.
Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.