Modifiers LT and RT: Left-Side and Right-Side Procedures
Governs use and reimbursement impact of CPT/HCPCS procedure modifiers LT and RT for indicating left or right side procedures for Anthem Blue Cross Medicare Advantage providers in California.
No material clinical or coverage changes in this revision.
When LT/RT Modifiers Are Appropriate
LT/RT modifier coverage criteria
Conditions under which modifiers LT and RT are acceptable and their reimbursement effect:
Required
- Allowed to append LT and/or RT to procedure codes to indicate side of body when appropriate
- Reimbursement is based on 100% of the fee schedule or contracted/negotiated rate; LT/RT modifiers are informational and do not increase or decrease reimbursement
- Do not use LT or RT for bilateral procedures or with procedure codes whose descriptors indicate bilateral or unilateral/bilateral; LT/RT do not indicate bilateral services
- Claims with LT and RT indicating procedures performed on both sides are subject to multiple surgery rules
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.