Billing and Collections Q&A

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By Lisa Lake-Salmon
Lisa Lake-Salmon

Running an O&P practice is complicated enough without having to deal with frequent denials. This month's column tackles your questions regarding Medicare denials due to incorrect knee-brace modifiers, denials due to incorrect prosthetic modifiers, and denials due to incorrect coding of lumbar corsets, plus information on billing for custom compression stockings.

Q: We are a physician's office in Georgia and recently started billing for knee braces. We billed Medicare for L-1832 and were told by the brace manufacturer that we could bill for addition codes for this brace. Some of our claims were denied because the addition codes are not covered, but some claims were paid. Why would they pay for some addition codes and not others for the same brace? I was also told that I did not have the correct modifier on my claim. I used RT for the right leg.

A: When billing Medicare for a knee orthosis, you must bill with the KX modifier along with RT or LT. Each brace has specific addition codes that are eligible for separate payment. When billing for an L-1832, the addition codes that are payable are L-2397, L-2795, and L-2810. For a complete list of base codes along with the addition codes that are eligible for separate payment, visit

Q: I received a denial from Region D for invalid modifier. When I contacted customer service, I was told that the RP modifier is no longer valid and I should use the new modifiers. Do you know what modifiers I should use when replacing a prosthetic component?

A: There are two modifiers that replaced the RP modifier when billing Medicare. The RA modifier is used to describe the replacement of an entire prosthesis. The RB modifier is used when you are replacing a component of the prosthesis.

Q: Can you help us understand how to bill Medicare for custom compression stockings? We need to better understand the following: DX, compression level, and product. It has been our understanding that Medicare will pay for 40-50 mmHg if the patient has an ulcer.

A: A gradient compression stocking—A-6531 (below-knee 30-40 mmHg), A-6532 (below-knee 40-50 mmHg), and A-6545 (compression wrap below-knee 30-50 mmHg)—is covered when it is used in the treatment of an open venous-stasis ulcer (DX codes 459.31 or 459.33). When billing these codes, you must use the AW modifier along with RT or LT.

Q: We fit a lot of lumbar corsets (L-0628) and have always used the KX modifier. We are now experiencing multiple denials due to incorrect coding. Do you have any idea why our claims are now being denied?

A: Effective April 1, 2009, when billing Medicare for a spinal garment (L-0628) that is made primarily of non-elastic material (cotton or nylon) or has a rigid posterior panel, the claim must be billed with the CG modifier (policy criteria applied).

Lisa Lake-Salmon is the executive vice president of Acc-Q-Data, which provides billing, collections, and practice management software. She has been serving the O&P profession for more than a decade. We invite readers to write in and ask any questions they may have regarding billing, collections, or related subjects. While every attempt has been made to ensure accuracy, The O&P EDGE is not responsible for errors. For more information, contact or visit