G04.91: Myelitis, unspecified
G04.91, myelitis, unspecified, is listed as a covered diagnosis in 6 Medicare billing and coding articles that apply to 12 HCPCS Level II codes, including U0002 (2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19)…), U0001 (Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr…), E0783 (Infusion pump system, implantable, programmable (includes…). 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 4 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 G04.91 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| U0002 | 2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19), any technique, multiple types or subtypes (includes all targets), non-cdc | Carrier judgment | — | 4 |
| U0001 | Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr diagnostic panel | Carrier judgment | — | 4 |
| 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 |
| G0255 | Current perception threshold/sensory nerve conduction test, (snct) per limb, any nerve | Non-covered by Medicare | Not covered | 1 |
Medicare policy articles listing G04.91
- A58710: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (Palmetto GBA (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58720: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58761: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- A58747: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing (CGS Administrators, LLC (MAC - Part A, MAC - Part B); 2 Level II codes). LCD with the same title: L38988, L39001, L39038, L39044
- 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
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 G04 diagnoses (Encephalitis, myelitis and encephalomyelitis)
- G04.90 — Encephalitis and encephalomyelitis, unspecified
- G04.01 — Postinfectious acute disseminated encephalitis and encephalomyelitis…
- G04.02 — Postimmunization acute disseminated encephalitis, myelitis and…
- G04.1 — Tropical spastic paraplegia
- G04.30 — Acute necrotizing hemorrhagic encephalopathy, unspecified
- G04.31 — Postinfectious acute necrotizing hemorrhagic encephalopathy
- G04.32 — Postimmunization acute necrotizing hemorrhagic encephalopathy
- G04.39 — Other acute necrotizing hemorrhagic encephalopathy
- G04.81 — Other encephalitis and encephalomyelitis
- G04.82 — Acute flaccid myelitis
- G04.89 — Other myelitis
Frequently asked questions
Does Medicare cover G04.91 (Myelitis, unspecified)?
Medicare covers items and services, not diagnoses. 6 Medicare billing and coding articles list G04.91 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 G04.91?
The Level II codes from the policies most specific to this diagnosis are U0002 (2019-ncov coronavirus, sars-cov-2/2019-ncov (covid-19)…, 4 articles); U0001 (Cdc 2019 novel coronavirus (2019-ncov) real-time rt-pcr…, 4 articles); 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). Code choice depends on the item supplied; check each code's descriptor.
What does Medicare pay for equipment billed with G04.91?
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 G04.91?
A58710 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing); A58720 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing); A58761 (Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing), and 3 more articles.
What is ICD-10-CM code G04.91?
G04.91 is the ICD-10-CM code for myelitis, unspecified, in category G04 (Encephalitis, myelitis and encephalomyelitis), chapter 6: Diseases of the nervous system.
Next steps
- Run a reimbursement report for a device billed under U0002
- Watch U0002 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for U0002
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 6: Diseases of the nervous system · All diagnoses · HCPCS lookup