S40.842A: External constriction of left upper arm, initial encounter
S40.842A, external constriction of left upper arm, initial encounter, is listed as a covered diagnosis in 3 Medicare billing and coding articles that apply to 8 HCPCS Level II codes, including G0329 (Electromagnetic therapy, to one or more areas for chronic…), G0281 (Electrical stimulation, (unattended), to one or more…), J1670 (Injection, tetanus immune globulin, human, up to 250 units). The articles come from 3 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 S40.842A as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| 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 |
| 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 |
| J1670 | Injection, tetanus immune globulin, human, up to 250 units | Special coverage instructions apply | — | 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 S40.842A
- A55909: Billing and Coding: Wound Care (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L35125, L37166, L37228
- A52438: Billing and Coding: Tetanus Immunization (CGS Administrators, LLC (MAC - Part A, MAC - Part B); 1 Level II codes)
- 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 S40 diagnoses (Superficial injury of shoulder and upper arm)
- S40.841A — External constriction of right upper arm, initial encounter
- S40.241A — External constriction of right shoulder, initial encounter
- S40.242A — External constriction of left shoulder, initial encounter
- S40.251A — Superficial foreign body of right shoulder, initial encounter
- S40.252A — Superficial foreign body of left shoulder, initial encounter
- S40.271A — Other superficial bite of right shoulder, initial encounter
- S40.272A — Other superficial bite of left shoulder, initial encounter
Frequently asked questions
Does Medicare cover S40.842A (External constriction of left upper arm, initial encounter)?
Medicare covers items and services, not diagnoses. 3 Medicare billing and coding articles list S40.842A 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 S40.842A?
The Level II codes from the policies most specific to this diagnosis are G0329 (Electromagnetic therapy, to one or more areas for chronic…, 2 articles); G0281 (Electrical stimulation, (unattended), to one or more…, 1 article); J1670 (Injection, tetanus immune globulin, human, up to 250 units, 1 article); G0151 (Services performed by a qualified physical therapist in…, 1 article); G0157 (Services performed by a qualified physical therapist…, 1 article). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list S40.842A?
A55909 (Billing and Coding: Wound Care); A52438 (Billing and Coding: Tetanus Immunization); A53058 (Billing and Coding: Home Health Physical Therapy).
What is ICD-10-CM code S40.842A?
S40.842A is the ICD-10-CM code for external constriction of left upper arm, initial encounter, in category S40 (Superficial injury of shoulder and upper arm), chapter 19: Injury, poisoning and other consequences of external causes.
Next steps
- Run a reimbursement report for a device billed under G0329
- Watch G0329 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for G0329
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 19: Injury, poisoning and other consequences of external causes · All diagnoses · HCPCS lookup