Billing and Collections Q&A

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By Lisa Lake

Billing for O&P devices can be complicated. Count on Got FAQs? to help answer your toughest questions. This month's column focuses on the documentation you need to successfully bill Medicare for knee braces and therapeutic shoes and inserts.


Q:  I work for an orthotist and we consistently receive letters requesting additional documentation before claims are paid. I am relatively new to this office and want to ensure our documentation is on point. We receive the most additional documentation letters for prefabricated and custom-fabricated knee braces, Healthcare Common Procedure Coding System (HCPCS) codes L-1831, L-1832, L-1833, L-1840, L-1843, L-1844, and L-1851. I worked in a physician's office for ten years, but this is different. Any insight is appreciated.


A:  According to Medicare, for a knee orthosis to be considered for coverage, the orthosis must be a rigid or semi-rigid device; and be used for the purpose of supporting a weak or deformed body member or restricting or eliminating motion in a diseased or injured part of the body. L-1831 describes a prefabricated knee orthosis with joint(s) that lock the knee into a particular position. L-1832 and L-1833 describe a prefabricated knee orthosis typically used during early rehabilitation for controlling range of motion of the knee joint following surgery.


L-1840 describes a custom-fabricated knee orthosis used to reduce forces to the joint and protect the ligaments of the knee through control of rotational and medial-lateral torsion. L-1843, L-1851, and L-1844 describe, respectively, two prefabricated and one custom-fabricated knee orthoses that have a single upright and are typically used to support the knee through the application of a medial- or lateral-directed force in patients with unicompartmental knee osteoarthritis.


Coverage of prefabricated HCPCS codes L-1832, L-1833, L-1843, and L-1851 will be determined by whether the beneficiary had a recent injury or surgical procedure, so your documentation must include this. Your paperwork should reflect that the patient is ambulatory and has knee instability. Your examination of the patient and your objective description of joint laxity (e.g., varus/valgus instability, anterior/posterior Drawer test) are required. Prefabricated code L-1831 coverage requires your documentation shows that the patient has flexion or extension contractures of the knee with movement on passive range of motion testing of at least 10 degrees (a non-fixed contracture).


Codes for custom-fabricated devices L-1840 and L-1844 have coverage criteria similar to the same type of prefabricated knee orthosis. However, there must also be documentation in your records to medically describe why your patient needs a custom-fabricated device instead of a prefabricated knee orthosis. Examples of situations that meet the criterion for a custom-fabricated knee orthosis include but are not limited to: 1. Deformity of the leg or knee; 2. Size of thigh and calf; 3. Minimal muscle mass upon which to suspend an orthosis. For the complete medical policy on knee orthoses visit


Q:  I work for an O&P facility in Louisiana. We are beginning to provide shoes and inserts for patients who may have coverage through Medicare. I was under the impression that shoes and inserts were not covered unless the patient has a diabetes diagnosis. Can you please clarify this for us?


A:  Orthopedic shoes are reimbursed as a Medicare benefit under very limited circumstances. For coverage to be considered, the beneficiary's records should stipulate that the use of the orthopedic shoe(s) is attached to a brace.


For persons with diabetes only, substitution of modification(s) of custom-molded or depth shoes may be covered instead of obtaining a pair(s) of inserts in any combination. Payment for the modification(s) may not exceed the limit set for the inserts for which the individual is entitled. In other words, orthopedic shoes, inserts, and modifications may only be billed when attached to a brace, in which case the shoes, inserts, and/or modifications must be billed by the supplier billing the brace or as a substitute for inserts for beneficiaries entitled to therapeutic shoes and inserts by virtue of a diabetes diagnosis. For the complete medical policy on orthopedic footwear, visit


Lisa Lake is an independent medical consultant with over 24 years of experience in the O&P industry, increasing providers' revenue by product recommendation, product and billing knowledge, and contract access assistance. She is a nationally recognized speaker on billing reimbursement and government compliancy. While every attempt has been made to ensure accuracy, The O&P EDGE is not responsible for errors. Lake can be contacted at