M21.831: Other specified acquired deformities of right forearm
M21.831, other specified acquired deformities of right forearm, is listed as a covered diagnosis in 7 Medicare billing and coding articles that apply to 8 HCPCS Level II codes, including G0283 (Electrical stimulation (unattended), to one or more areas…), G0152 (Services performed by a qualified occupational therapist…), G0158 (Services performed by a qualified occupational therapist…). The articles come from 5 Medicare contractors. 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 M21.831 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 |
| 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 |
| 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 | — | 1 |
| G0255 | Current perception threshold/sensory nerve conduction test, (snct) per limb, any nerve | Non-covered by Medicare | Not covered | 5 |
Medicare policy articles listing M21.831
- A57307: Billing and Coding: Nerve Conduction Studies and Electromyography (CGS Administrators, LLC (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L34594, L34859, L35048, L35081
- A57478: Billing and Coding: Nerve Conduction Studies and Electromyography (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L34594, L34859, L35048, L35081
- A54969: Billing and Coding: Nerve Conduction Studies and Electromyography (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L34594, L34859, L35048, L35081
- A57668: Billing and Coding: Nerve Conduction Studies and Electromyography (Wellpoint Federal (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L34594, L34859, L35048, L35081
- A56619: Billing and Coding: Nerve Conduction Studies and Electromyography (Palmetto GBA (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L34594, L34859, L35048, L35081
- 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
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)
- M21.832 — Other specified acquired deformities of left forearm
- M21.861 — Other specified acquired deformities of right lower leg
- M21.862 — Other specified acquired deformities of left lower leg
- M21.071 — Valgus deformity, not elsewhere classified, right ankle
- M21.072 — Valgus deformity, not elsewhere classified, left ankle
- M21.171 — Varus deformity, not elsewhere classified, right ankle
- M21.172 — Varus deformity, not elsewhere classified, left ankle
- M21.331 — Wrist drop, right wrist
- M21.332 — Wrist drop, left wrist
- M21.371 — Foot drop, right foot
- M21.372 — Foot drop, left foot
- M21.511 — Acquired clawhand, right hand
- M21.512 — Acquired clawhand, left hand
- M21.531 — Acquired clawfoot, right foot
- M21.532 — Acquired clawfoot, left foot
- M21.541 — Acquired clubfoot, right foot
- M21.542 — Acquired clubfoot, left foot
- M21.6X1 — Other acquired deformities of right foot
- M21.6X2 — Other acquired deformities of left foot
- 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
- M21.961 — Unspecified acquired deformity of right lower leg
- M21.962 — Unspecified acquired deformity of left lower leg
Frequently asked questions
Does Medicare cover M21.831 (Other specified acquired deformities of right forearm)?
Medicare covers items and services, not diagnoses. 7 Medicare billing and coding articles list M21.831 as a covered diagnosis for 8 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 M21.831?
The Level II codes from the policies most specific to this diagnosis are G0283 (Electrical stimulation (unattended), to one or more areas…, 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); G2169 (Services performed by an occupational therapist assistant…, 1 article). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list M21.831?
A57307 (Billing and Coding: Nerve Conduction Studies and Electromyography); A57478 (Billing and Coding: Nerve Conduction Studies and Electromyography); A54969 (Billing and Coding: Nerve Conduction Studies and Electromyography), and 4 more articles.
What is ICD-10-CM code M21.831?
M21.831 is the ICD-10-CM code for other specified acquired deformities of right forearm, 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
Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.
Chapter 13: Diseases of the musculoskeletal system and connective tissue · All diagnoses · HCPCS lookup