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Claim Submission of a Right and Left Modifier

Provider Administrative Policy

Claims Submission
Policy Date
November 2007
Revised/September 2011
Provider Type(s)
All Providers  


Our provider administrative policies contain information regarding claims submission, reimbursement, and other information in order to achieve an efficient relationship with our providers. These policies are not an authorization or explanation of benefits. Blue Cross of Idaho retains the right to add to, delete from and otherwise modify this policy in accordance with our provider contracts.


Claim Submission of a Right and Left Modifier

In most circumstances, bilateral services should be billed as one line item with a modifier 50 and a unit of one.  When a bilateral service must be reported with left and right modifiers, a modifier 51 must also be appended to one of the line items.  Only append modifiers (RT) and (LT) when necessary and when the base CPT or HCPCS code describes a service applicable to both sides.

The CPT manual defines 'Add On' and 'Modifier 51 Exempt' procedures. For all other procedures, professional providers are required to assign a modifier 51, appended in the first position, when submitting multiple surgical codes. Append the right (RT) or left (LT) modifier in the second position when billing any of the following combinations: 

· Procedure code with (RT) and another procedure code with (LT) on the same claim

· Procedure code with (RT) and another procedure code with (RT) on the same claim

· Procedure code with (LT) and another procedure code with (LT) on the same claim

If you submit paper claims without the modifier 51 on secondary and subsequent procedures, we will either return the claim to you or append the modifier 51 to the secondary procedure code where it is required.

Please note: When submitting right (RT) and left (LT) modifiers with HCPCS and radiology codes (70010-79999), modifier 51 is not required.

Refer to PAP257 for additional information related to multiple surgeries.

Policy History

Date Action Reason
September 2011 Revised Added/removed language regarding modifier 51
November 2008 Revised Language clarification

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