CurrentPremera BluecrossPolicy CP.PP.223.v3.2

Modifier 50 - Bilateral Procedure

Defines when Premera recognizes Modifier 50 on professional claims to indicate bilateral procedures and how those services are billed and reimbursed; applies to Premera lines of business and related products and providers submitting professional claims.

Policy Summary

PayerPremera Bluecross

PolicyModifier 50 - Bilateral Procedure

Policy CodePolicy CP.PP.223.v3.2

Change TypeClarification updates (no material coverage changes)

Effective Date

Next Review Date

Key ActionAppend modifier 50 to a single line with one unit when a bilateral procedure is performed on identical anatomic sites on opposite sides during the same session; do not bill RT/LT on the same line as 50.

SourceLink

POLICY UPDATE CHANGES

Clarified the sourcing used to determine bilateral surgery (NPFS bilateral surgery flag).

Clarified the descriptions of the 'Bilateral Flag' from the CMS National Physician Fee Schedule.

Clarified how providers should bill when they act as a co-surgeon on a bilateral surgical procedure.

Clarified laterality and correct use of modifiers LT, RT and 50.

150%reimbursement adjustment when modifier 50 applies

NPFS 0,1,2,3,9CMS NPFS flags used

Premera & affiliatesLines of business covered

02/06/26last review

When Modifier 50 Is Recognized

Modifier 50 coverage criteria

Covered when ALL of the following apply:

Modifier 50 is recognized when a bilateral procedure has been performed on identical anatomic sites on opposite sides of the body during the same operative session or on the same day by the same provider and must be billed on a single claim line with one unit of service.

Do not bill RT or LT on the same claim line as Modifier 50; use LT/RT only when a procedure is performed on a single anatomic side.

Do not append Modifier 50 to procedures/codes that are bilateral by definition or whose descriptions include terminology such as 'bilateral,' 'unilateral or bilateral,' or 'one or both.'

For site-specific anatomic locations of the eyelids, toes, and fingers, use site-specifying modifiers instead of Modifier 50 where applicable.

Policy Summary

PayerPremera Bluecross

PolicyModifier 50 - Bilateral Procedure

Policy CodePolicy CP.PP.223.v3.2

Change TypeClarification updates (no material coverage changes)

Effective Date

Next Review Date

SourceLink

On This Page

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.

Billing Instructions and Provider Responsibilities

Billing Rule

Billing actions for providers — use Modifier 50 and co‑surgeon guidance

Append Modifier 50 to a single claim line with one unit when a bilateral procedure is performed on identical anatomic sites on opposite sides during the same operative session or same day by the same provider; do not bill RT or LT on that same claim line. For site-specific locations of the eyelids, toes, and fingers, use site-specifying modifiers instead of Modifier 50. When acting as co-surgeons on opposite anatomic locations, each surgeon should bill the same procedure code appended with modifier 62 (Two Surgeons); assistant surgeon modifiers (80, 81, 82, AS) are not appropriate in that situation.

Bill Modifier 50 on a single line with one unit when applicable; do not include RT/LT on that line. [[source]]
Do not use Modifier 50 for codes that are bilateral by definition or when NPFS bilateral flag indicates not to (see NPFS flags guidance). [[source]]
Use site-specific modifiers for eyelids, toes, and fingers instead of Modifier 50 where applicable. [[source]]
If co-surgeons operate on opposite sides, each bills the same code with modifier 62 (Two Surgeons); do not use assistant surgeon modifiers 80/81/82/AS. [[source]]

Key Modifier Definitions

Modifier 50 — Definition and billing expectations

Definition of Modifier 50Modifier 50 indicates a bilateral procedure performed on identical anatomic sites on opposite sides of the body during the same operative session or on the same day by the same provider; it should be billed on a single line with one unit of service.

Billing expectation — unitsWhen Modifier 50 is appended, bill the procedure on a single claim line with one unit; do not bill RT/LT on the same code on the same claim line.

Site-specific exceptionsFor eyelids, toes, and fingers, use site-specifying modifiers instead of Modifier 50 where applicable.

Do not use when bilateral by definitionDo not use Modifier 50 on procedures/codes that are bilateral by definition or whose descriptions already indicate bilateral (e.g., 'bilateral', 'unilateral or bilateral', 'one or both').

LT / RT modifiers — Guidance

Use of LT/RTModifiers LT and RT are not used to indicate a bilateral surgical procedure; use LT or RT when a procedure is performed on only one anatomic side.

Diagnosis laterality guidancePer ICD-10-CM guidelines, some diagnosis codes indicate laterality; if no bilateral diagnosis code exists for a bilateral condition, assign separate left and right diagnosis codes.

Conflict consequencesConflicts between the laterality of the diagnosis code and the laterality of the procedure code (as defined by site-specific modifiers) will result in non-reimbursement.

OpenPayer

Modifier 50 - Bilateral Procedure

When Modifier 50 Is Recognized

Coding Guidance and Reimbursement Adjustment

Billing Instructions and Provider Responsibilities

Key Modifier Definitions