M43.21: Fusion of spine, occipito-atlanto-axial region
M43.21, fusion of spine, occipito-atlanto-axial region, is listed as a covered diagnosis in 3 Medicare billing and coding articles that apply to 12 HCPCS Level II codes, including E0783 (Infusion pump system, implantable, programmable (includes…), E0786 (Implantable programmable infusion pump, replacement…), E0782 (Infusion pump, implantable, non-programmable (includes all…). 4 of these codes have a 2026 DMEPOS fee schedule amount; E0783 pays $9,917.33 to $11,667.45 (NU) depending on the state. The articles come from 2 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 M43.21 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| E0783 | Infusion pump system, implantable, programmable (includes all components, e.g., pump, catheter, connectors, etc.) | Special coverage instructions apply | $9,917.33–$11,667.45 (NU) | 1 |
| E0786 | Implantable programmable infusion pump, replacement (excludes implantable intraspinal catheter) | Special coverage instructions apply | $10,969.75–$11,380.88 (NU) | 1 |
| E0782 | Infusion pump, implantable, non-programmable (includes all components, e.g., pump, catheter, connectors, etc.) | Special coverage instructions apply | $5,200.92–$6,118.73 (NU) | 1 |
| E0785 | Implantable intraspinal (epidural/intrathecal) catheter used with implantable infusion pump, replacement | Special coverage instructions apply | $572.38–$673.39 (KF) | 1 |
| J7999 | Compounded drug, not otherwise classified | Special coverage instructions apply | — | 1 |
| J2278 | Injection, ziconotide, 1 microgram | Special coverage instructions apply | — | 1 |
| J2274 | Injection, morphine sulfate, preservative-free for epidural or intrathecal use, 10 mg | Special coverage instructions apply | — | 1 |
| A4220 | Refill kit for implantable infusion pump | Special coverage instructions apply | — | 1 |
| J9200 | Injection, floxuridine, 500 mg | Special coverage instructions apply | — | 1 |
| A9585 | Injection, gadobutrol, 0.1 ml | Carrier judgment | — | 1 |
| Q9953 | Injection, iron-based magnetic resonance contrast agent, per ml | Special coverage instructions apply | — | 1 |
| G0255 | Current perception threshold/sensory nerve conduction test, (snct) per limb, any nerve | Non-covered by Medicare | Not covered | 1 |
Medicare policy articles listing M43.21
- 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
- A56695: Billing and Coding: Implantable Infusion Pump (Palmetto GBA (MAC - Part B); 9 Level II codes). LCD with the same title: L33461
- A57206: Billing and Coding: Lumbar MRI (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L34220
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 M43 diagnoses (Other deforming dorsopathies)
- M43.22 — Fusion of spine, cervical region
- M43.23 — Fusion of spine, cervicothoracic region
- M43.24 — Fusion of spine, thoracic region
- M43.25 — Fusion of spine, thoracolumbar region
- M43.26 — Fusion of spine, lumbar region
- M43.27 — Fusion of spine, lumbosacral region
- M43.28 — Fusion of spine, sacral and sacrococcygeal region
- M43.01 — Spondylolysis, occipito-atlanto-axial region
- M43.02 — Spondylolysis, cervical region
- M43.03 — Spondylolysis, cervicothoracic region
- M43.04 — Spondylolysis, thoracic region
- M43.05 — Spondylolysis, thoracolumbar region
- M43.06 — Spondylolysis, lumbar region
- M43.07 — Spondylolysis, lumbosacral region
- M43.08 — Spondylolysis, sacral and sacrococcygeal region
- M43.09 — Spondylolysis, multiple sites in spine
- M43.11 — Spondylolisthesis, occipito-atlanto-axial region
- M43.12 — Spondylolisthesis, cervical region
- M43.13 — Spondylolisthesis, cervicothoracic region
- M43.14 — Spondylolisthesis, thoracic region
- M43.15 — Spondylolisthesis, thoracolumbar region
- M43.16 — Spondylolisthesis, lumbar region
- M43.17 — Spondylolisthesis, lumbosacral region
- M43.18 — Spondylolisthesis, sacral and sacrococcygeal region
- M43.19 — Spondylolisthesis, multiple sites in spine
- M43.6 — Torticollis
- M43.8X1 — Other specified deforming dorsopathies, occipito-atlanto-axial region
- M43.8X2 — Other specified deforming dorsopathies, cervical region
- M43.8X3 — Other specified deforming dorsopathies, cervicothoracic region
- M43.8X4 — Other specified deforming dorsopathies, thoracic region
Frequently asked questions
Does Medicare cover M43.21 (Fusion of spine, occipito-atlanto-axial region)?
Medicare covers items and services, not diagnoses. 3 Medicare billing and coding articles list M43.21 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 M43.21?
The Level II codes from the policies most specific to this diagnosis are E0783 (Infusion pump system, implantable, programmable (includes…, 1 article); E0786 (Implantable programmable infusion pump, replacement…, 1 article); E0782 (Infusion pump, implantable, non-programmable (includes all…, 1 article); E0785 (Implantable intraspinal (epidural/intrathecal) catheter…, 1 article); J7999 (Compounded drug, not otherwise classified, 1 article). Code choice depends on the item supplied; check each code's descriptor.
What does Medicare pay for equipment billed with M43.21?
Under the 2026 DMEPOS fee schedule (non-rural state fees): E0783 $9,917.33 to $11,667.45 (NU); E0786 $10,969.75 to $11,380.88 (NU); E0782 $5,200.92 to $6,118.73 (NU); E0785 $572.38 to $673.39 (KF). Medicare pays 80% of the allowed amount after the Part B deductible.
Which Medicare policy articles list M43.21?
A56619 (Billing and Coding: Nerve Conduction Studies and Electromyography); A56695 (Billing and Coding: Implantable Infusion Pump); A57206 (Billing and Coding: Lumbar MRI).
What is ICD-10-CM code M43.21?
M43.21 is the ICD-10-CM code for fusion of spine, occipito-atlanto-axial region, in category M43 (Other deforming dorsopathies), chapter 13: Diseases of the musculoskeletal system and connective tissue.
Next steps
- Run a reimbursement report for a device billed under E0783
- Watch E0783 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for E0783
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