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Linda Collins Blogger

Use the Correct Modifier

Posted by Linda Collins | December 09, 2015

​Modifier mistakes, improperly used or omitted, are the number 1 reason for front end claims rejections. Are you using all the correct modifiers for the HCPCS codes you bill?

HCPCS is a standardized coding system that is used primarily to identify products, supplies, and services such as durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS.) There are hundreds of HCPCS codes to aid in specifically identifying the product being delivered. However, the codes themselves may not be detailed enough so modifiers, allow for greater accuracy in coding and billing. The modifiers are always two characters and are added to the base code with a hyphen.

Common modifiers for orthotic and prosthetic claims include:

CG - elastic garments which do not meet the statutory definition of a brace. Hand orthoses billed with L3923, and spinal orthoses billed with L0450, L0454, L0625, and L0628 must use the CG modifier.

GA - submitted on claims when the supplier has an Advance Beneficiary Notice on file. An ABN is a written notice a supplier gives to a Medicare beneficiary before items or services are furnished when the supplier believes that Medicare will not pay because there is a lack of medical necessity.

GK - reasonable and necessary item ordered when a piece of equipment has been upgraded. (See The Right Way to Give a Custom Brace.)

GY - item is statutorily excluded from Medicare benefits. A4466 is one code always billed with this modifier.

KV - used by physicians and treating practitioners who are not contract suppliers and who furnish walkers and related accessories to beneficiaries in a CBA. Walkers that are appropriately furnished in accordance with this exception will be paid at the single payment amount.

KX - specific required documentation on file. Suppliers must add a "KX" modifier to knee orthoses base and addition codes only if all of the coverage criteria in LCD have been met and appropriate documentation is retained in the supplier's files.

LT - Left side

RT - Right side

K0-K4 - functional level. All prosthetic claims require the use of a functional level modifier


Avoid the #1 claim mistake by using the correct modifier(s) with your HCPCS codes.

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