M21.731: Unequal limb length (acquired), right ulna
M21.731, unequal limb length (acquired), right ulna, is listed as a covered diagnosis in 3 Medicare billing and coding articles that apply to 12 HCPCS Level II codes, including G0283 (Electrical stimulation (unattended), to one or more areas…), G0329 (Electromagnetic therapy, to one or more areas for chronic…), G0152 (Services performed by a qualified occupational therapist…). The articles come from 1 Medicare contractor. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.
HCPCS Level II codes with M21.731 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| G0283 | Electrical stimulation (unattended), to one or more areas for indication(s) other than wound care, as part of a therapy plan of care | Carrier judgment | — | 2 |
| G0329 | Electromagnetic therapy, to one or more areas for chronic stage iii and stage iv pressure ulcers, arterial ulcers, diabetic ulcers and venous stasis ulcers not demonstrating measurable signs of healing after 30 days of conventional care as part of a therapy plan of care | Carrier judgment | — | 2 |
| G0152 | Services performed by a qualified occupational therapist in the home health or hospice setting, each 15 minutes | Carrier judgment | — | 1 |
| G0158 | Services performed by a qualified occupational therapist assistant in the home health or hospice setting, each 15 minutes | Carrier judgment | — | 1 |
| G0160 | Services performed by a qualified occupational therapist, in the home health setting, in the establishment or delivery of a safe and effective occupational therapy maintenance program, each 15 minutes | Carrier judgment | — | 1 |
| G2169 | Services performed by an occupational therapist assistant in the home health setting in the delivery of a safe and effective occupational therapy maintenance program, each 15 minutes | Carrier judgment | — | 1 |
| G0281 | Electrical stimulation, (unattended), to one or more areas, for chronic stage iii and stage iv pressure ulcers, arterial ulcers, diabetic ulcers, and venous stasis ulcers not demonstrating measurable signs of healing after 30 days of conventional care, as part of a therapy plan of care | Carrier judgment | — | 1 |
| G0151 | Services performed by a qualified physical therapist in the home health or hospice setting, each 15 minutes | Carrier judgment | — | 1 |
| G0157 | Services performed by a qualified physical therapist assistant in the home health or hospice setting, each 15 minutes | Carrier judgment | — | 1 |
| G0159 | Services performed by a qualified physical therapist, in the home health setting, in the establishment or delivery of a safe and effective physical therapy maintenance program, each 15 minutes | Carrier judgment | — | 1 |
| G2168 | Services performed by a physical therapist assistant in the home health setting in the delivery of a safe and effective physical therapy maintenance program, each 15 minutes | Carrier judgment | — | 1 |
| L1972 | Ankle foot orthosis, plastic or other material with ankle joint, with or without dorsiflexion assist, prefabricated, off-the shelf | Carrier judgment | — | 1 |
Medicare policy articles listing M21.731
- A53057: Billing and Coding: Home Health Occupational Therapy (Palmetto GBA (HHH MAC); 5 Level II codes). LCD with the same title: L34560
- A53064: Billing and Coding: Outpatient Occupational Therapy (Palmetto GBA (MAC - Part A); 3 Level II codes). LCD with the same title: L34427
- A53058: Billing and Coding: Home Health Physical Therapy (Palmetto GBA (HHH MAC); 6 Level II codes). LCD with the same title: L34564
A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.
Other M21 diagnoses (Other acquired deformities of limbs)
- M21.732 — Unequal limb length (acquired), left ulna
- M21.733 — Unequal limb length (acquired), right radius
- M21.734 — Unequal limb length (acquired), left radius
- M21.721 — Unequal limb length (acquired), right humerus
- M21.722 — Unequal limb length (acquired), left humerus
- M21.751 — Unequal limb length (acquired), right femur
- M21.752 — Unequal limb length (acquired), left femur
- M21.761 — Unequal limb length (acquired), right tibia
- M21.762 — Unequal limb length (acquired), left tibia
- M21.763 — Unequal limb length (acquired), right fibula
- M21.764 — Unequal limb length (acquired), left fibula
- M21.021 — Valgus deformity, not elsewhere classified, right elbow
- M21.022 — Valgus deformity, not elsewhere classified, left elbow
- M21.051 — Valgus deformity, not elsewhere classified, right hip
- M21.052 — Valgus deformity, not elsewhere classified, left hip
- M21.061 — Valgus deformity, not elsewhere classified, right knee
- M21.062 — Valgus deformity, not elsewhere classified, left knee
- M21.071 — Valgus deformity, not elsewhere classified, right ankle
- M21.072 — Valgus deformity, not elsewhere classified, left ankle
- M21.121 — Varus deformity, not elsewhere classified, right elbow
- M21.122 — Varus deformity, not elsewhere classified, left elbow
- M21.151 — Varus deformity, not elsewhere classified, right hip
- M21.152 — Varus deformity, not elsewhere classified, left hip
- M21.161 — Varus deformity, not elsewhere classified, right knee
- M21.162 — Varus deformity, not elsewhere classified, left knee
- M21.171 — Varus deformity, not elsewhere classified, right ankle
- M21.172 — Varus deformity, not elsewhere classified, left ankle
- M21.211 — Flexion deformity, right shoulder
- M21.212 — Flexion deformity, left shoulder
- M21.221 — Flexion deformity, right elbow
Frequently asked questions
Does Medicare cover M21.731 (Unequal limb length (acquired), right ulna)?
Medicare covers items and services, not diagnoses. 3 Medicare billing and coding articles list M21.731 as a covered diagnosis for 12 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.
Which HCPCS codes can be billed with ICD-10 M21.731?
The Level II codes from the policies most specific to this diagnosis are G0283 (Electrical stimulation (unattended), to one or more areas…, 2 articles); G0329 (Electromagnetic therapy, to one or more areas for chronic…, 2 articles); G0152 (Services performed by a qualified occupational therapist…, 1 article); G0158 (Services performed by a qualified occupational therapist…, 1 article); G0160 (Services performed by a qualified occupational therapist…, 1 article). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list M21.731?
A53057 (Billing and Coding: Home Health Occupational Therapy); A53064 (Billing and Coding: Outpatient Occupational Therapy); A53058 (Billing and Coding: Home Health Physical Therapy).
What is ICD-10-CM code M21.731?
M21.731 is the ICD-10-CM code for unequal limb length (acquired), right ulna, in category M21 (Other acquired deformities of limbs), chapter 13: Diseases of the musculoskeletal system and connective tissue.
Next steps
- Run a reimbursement report for a device billed under G0283
- Watch G0283 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for G0283
Compiled by Caduvo from public CMS (Medicare) records, ICD-10-CM FY2026, HCPCS release October 2026, 2026 fee schedule (non-rural state fees). Not reviewed or endorsed by CMS. Not billing or legal advice. Report an error. Data and corrections policy.
Chapter 13: Diseases of the musculoskeletal system and connective tissue · All diagnoses · HCPCS lookup