Retired - LIM Innovation Infinite Socket - Correct Coding - Revised
DME MAC Joint Publication
Infinite Socket™ (LIM innovations) is an open-socket design that has distinct below knee and above knee products. These sockets are custom-fabricated from a model of the patient's residual limb and utilize struts that extend from a base to an adjustable brim enclosing an inner shell to form the primary structure of the socket.
The existing Healthcare Common Procedure Coding System (HCPCS) L-codes used for lower limb prosthetic sockets describe items which enclose the residual limb to provide the stability, proprioception, and suspension necessary for the effective use of the artificial limb. Although the LIM innovations Infinite Socket™ is different in design from traditional sockets described by the existing L-codes, it has been determined that the socket design has critical design elements to meet the coding requirements for the following HCPCS codes. The correct combinations of HCPCS codes to bill Medicare for these products are described in the tables below:
INFINITE SOCKET TT-S: (BK)
Base code for complete below knee (BK) prosthesis (choose one)
L5301 BELOW KNEE, MOLDED SOCKET, SHIN, SACH FOOT, ENDOSKELETAL SYSTEM
L5540 PREPARATORY, BELOW KNEE 'PTB' TYPE SOCKET, NON-ALIGNABLE SYSTEM, PYLON, NO COVER, SACH FOOT, LAMINATED SOCKET, MOLDED TO MODEL
Base code for BK socket replacement
L5700 REPLACEMENT, SOCKET, BELOW KNEE, MOLDED TO PATIENT MODEL
Addition codes that may be billed with one of the above BK base codes
L5629 ADDITION TO LOWER EXTREMITY, BELOW KNEE, ACRYLIC SOCKET
L5637 ADDITION TO LOWER EXTREMITY, BELOW KNEE, TOTAL CONTACT
L5940 ADDITION, ENDOSKELETAL SYSTEM, BELOW KNEE, ULTRA-LIGHT MATERIAL (TITANIUM, CARBON FIBER OR EQUAL)
INFINITE SOCKET T/F: ABOVE KNEE (AK)
Base code for complete above knee (AK) prosthesis (choose one)
L5321 - ABOVE KNEE, MOLDED SOCKET, OPEN END, SACH FOOT, ENDOSKELETAL SYSTEM, SINGLE AXIS KNEE
L5590 - PREPARATORY, ABOVE KNEE - KNEE DISARTICULATION ISCHIAL LEVEL SOCKET, NON-ALIGNABLE SYSTEM, PYLON NO COVER, SACH FOOT, LAMINATED SOCKET, MOLDED TO MODEL
Base code for AK Socket replacement
L5701 - REPLACEMENT, SOCKET, ABOVE KNEE/KNEE DISARTICULATION, INCLUDING ATTACHMENT PLATE, MOLDED TO PATIENT MODEL.
Addition codes that may be billed with one of the above AK codes
L5631 - ADDITION TO LOWER EXTREMITY, ABOVE KNEE OR KNEE DISARTICULATION, ACRYLIC SOCKET.
L5649 - ADDITION TO LOWER EXTREMITY, ISCHIAL CONTAINMENT/NARROW M-L SOCKET.
L5950 - ADDITION, ENDOSKELETAL SYSTEM, ABOVE KNEE, ULTRALIGHT MATERIAL (TITANIUM, CARBON FIBER OR EQUAL)
Shared Correct Coding
The additional HCPCS code describing the choice of suspension must be included on the same claim for the complete prosthesis or socket replacement, i.e., the claim that includes one of the above base codes. Use of more than one type of suspension per limb is considered incorrect billing (same/similar item).
Additional HCPCS codes describing features that may not be necessary on all sockets may only be used when the feature is provided for the individual beneficiary. The prosthetic record must include specific, detailed information justifying the need for each additional feature.
HCPCS code L5999 (LOWER EXTREMITY PROSTHESIS, NOT OTHERWISE SPECIFIED) must not be used to bill for any features or functions included in the socket or addition codes. Use of L5999 is incorrect coding (unbundling). Do not use (L5301, L5540, L5321, L5590) for billing a replacement socket for an existing prosthesis.
The use of L5910 (ADDITION, ENDOSKELETAL SYSTEM, BELOW KNEE, ALIGNABLE SYSTEM) or L5920 (ADDITION, ENDOSKELETAL SYSTEM, ABOVE KNEE OR HIP DISARTICULATION, ALIGNABLE SYSTEM) when providing a replacement socket are an incorrect addition, as they were previously reimbursed with the provision of the complete prosthesis.
Test sockets L5620 (ADDITION TO LOWER EXTREMITY, TEST SOCKET, BELOW KNEE) and L5624 (ADDITION TO LOWER EXTREMITY, TEST SOCKET, ABOVE KNEE) are not necessary for the production of these socket designs. Claims for L5620 or L5624 in conjunction with this socket design are considered incorrect billing.
Refer to the Lower Limb Prosthesis Local Coverage Determination and related Policy Article for additional information on coverage, coding and documentation for artificial limbs.
For questions about correct coding, contact the PDAC Contact Center at 877-735-1326 during the hours of 8:30 a.m.-4 p.m. CT, Monday through Friday, or email the PDAC by completing the DME PDAC Contact Form located on the PDAC website.
| Date | Update |
|---|---|
| 05/22/2015 | Published on PDAC website |
| 03/16/2016 | Revised |
| 12/28/2016 | Revised |
| 12/04/2019 | Revised to combine two articles (LIM Innovation Below Knee Socket - Correct Coding and LIM Innovations Infinite Socket - Correct Coding - Revised) |
| 04/09/2020 | Retired – content incorporated into the applicable Local Coverage Determination or related Policy Article |