Modifiers 50 & 51, bilateral vs. multiple procedures

This logic applies to claims submitted by facilities or professionals, in and out of network, for all Priority Health medical plans, including Medicaid and Medicare.

Modifier 50, bilateral procedures

Read the CPT code description closely. If it contains wording such as "unilateral" or "bilateral," the service is not valid for use of the 50 modifier.

  • Modifier is used when an identical service is performed on both sides of a paired organ.
  • Medicare bilateral procedure indicator is one or three.
  • Submit a single claim line with the appropriate code and modifier 50 appended; report total units as "1."
  • Multiple procedure reductions apply when multiple procedures are performed by the same physician on the same patient in the same surgical session.
  • RT and LT does not take the place of the 50 modifier and should only be used for services rendered on one side of a paired organ.

Bilateral radiology services

  • Radiology procedures are not subject to the bilateral pricing methodology.
  • Many radiology services can be reported with a bilateral modifier (services performed on both sides of a paired organ/structure), but read the CPT code description to ensure that it does not contain wording such as "unilateral" or "bilateral"
  • Bilateral radiology services should be reported based on units performed. These services are not subject to bilateral pricing and are reimbursed at fee schedule for each service. These can be billed on two lines with appropriate RT/LT modifier indicating sides. Claim lines billed for radiology services with modifier 50 and 1 unit will pay at the fee schedule for 1 unit. This would exclude CPT or HCPCS codes that are specifically identified as bilateral.

Modifier 50, exceptions

Ambulatory Surgical Centers (ASCs) must bill bilateral procedures separately. We'll deny professional claims from ASCs billed with Modifier 50. This edit is based on regulations from Center for Medicare & Medicaid Services and is applied across all lines of business.

How to bill bilateral procedures to ensure payment

When an ASC performs a bilateral procedure, they should bill as two procedures either as:

  • A single unit on two separate lines
  • Or with “2” in the units field on one line

Report the anatomical modifier to that best identifies the anatomical site (i.e., RT, LT, etc.) from the anatomical modifier list.

For example: If you perform lavage by cannulation; maxillary sinus (antrum puncture by natural ostium) (CPT code 31020) bilaterally in one operative session, bill 31020 either on two separate lines or on one line with ''2'' in the units field.

Modifier 51, multiple procedures 

  • Modifier 51 is not required on claim lines when multiple procedures are performed on the same day. Priority Health will apply multiple same-day surgical logic based on our fee schedule amounts.
  • Priority Health does not use Medicare's multiple endoscopic procedure methodology, but the services are subject to the same day multiple surgical reduction.
  • Modifier 51 does not apply to procedures classified as "add-on" or "Modifier 51 exempt."
  • Modifiers such as F- (finger), T- (toe), LT, and RT should be used to communicate locations and/or anatomical sites and will be subject to the multiple same-day procedures reduction.
  • The service with the highest allowed fee amount will be priced at the Priority Health fee schedule. Each additional same-day procedure will be priced at 50% of the fee, based on the lesser of billed charges or fee schedule amount.
  • Multiple same-day procedure reduction will be identified as "MSD" on your remittance advice.

Billing for multiple same-day procedures (MSD)

Multiple same-day procedures are services performed by a physician:

  • During the same encounter
  • For the same patient
  • On the same date 

Download our 2023 MSD codes

Download our 2024 MSD codes

Note: The MSD codes list above is subject to change. It was last updated in Dec. 14, 2023. We'll update the document as needed to reflect any future code changes. 

Guidelines

The multiple procedures modifier 51 is not required on claim lines when multiple procedures are performed on the same day. Priority Health will apply multiple same-day surgical logic based on our fee schedule amounts.

  • The service with the highest allowed fee amount will be priced at 100% of the Priority Health fee schedule.
  • Each additional same-day procedure (as defined above) will be priced at 50% of the fee (based on the lesser of billed charges or fee schedule amount.)
  • Services reported with modifiers such as 59, F1, F2, T1, T2, RT, LT, etc. will be subject to the multiple same-day procedures reduction.
  • This reduction will be identified as "MSD" on your remittance advice.

Exceptions

Add-on CPT codes and modifier 51-exempt codes can be found within Appendix F in the CPT manual OR the MPFSDB for a full listing and are not subject to the multiple same-day procedures reduction.