Degenerative spondylotic disease of the occipito-atlanto-axial region (C0–C2) producing spinal cord compression and myelopathic neurological deficits — not attributable to anterior spinal artery or vertebral artery compression syndromes (those fall under M47.0x).
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 15
- Region
- Spine
Documentation tips
What should appear in the chart to support M47.11.
Source · Editorial brief grounded in 5 cited references ↓
- Explicitly name the occipito-atlanto-axial region (C0–C2) in the assessment — vague 'cervical spondylosis' will not support M47.11 specificity.
- Document objective myelopathy findings: hyperreflexia, Babinski sign, Hoffman sign, clonus, myelopathic gait, or bowel/bladder dysfunction — not just neck pain.
- Correlate imaging to neurological findings: MRI T2 signal change at C0–C2, canal diameter measurements, or cord compression grade should appear in the note.
- If anterior spinal artery or vertebral artery compression is the documented mechanism, shift to M47.011 or M47.021 respectively — M47.11 is excluded from those scenarios.
- When vertebral subluxation coexists, assign M43.3–M43.5X9 as an additional code; the Type 1 Excludes note means you cannot fold both conditions into M47.11 alone.
Related CPT procedures
Procedure codes commonly billed with M47.11. Linking the right diagnosis to the right procedure is what establishes medical necessity.
Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis
Common coding pitfalls
The recurring mistakes coders make with M47.11 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M47.11 for cervical myelopathy below C2 — the occipito-atlanto-axial region covers only C0–C2; cervical region myelopathy codes to M47.12 and cervicothoracic to M47.13.
- Assigning M47.11 when the physician documents only neck pain or stiffness without documented myelopathy — that scenario belongs under M47.811 (spondylosis without myelopathy or radiculopathy, occipito-atlanto-axial region).
- Conflating radiculopathy with myelopathy: if nerve root symptoms dominate and cord signs are absent, M47.21 (radiculopathy, occipito-atlanto-axial region) is the correct code.
- Leaving the parent code M47.1 (non-billable) on the claim instead of drilling to the billable fifth-character code M47.11.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M47.11 applies when degenerative changes at the occiput–atlas–axis junction (C0–C2) directly compromise the spinal cord and generate objective myelopathy: upper motor neuron signs, gait disturbance, hand clumsiness, hyperreflexia, or bowel/bladder dysfunction. This is a rare but high-stakes location for spondylogenic myelopathy because the cord occupies a disproportionately large canal at this level and small encroachment can produce catastrophic deficits.
The Tabular List places M47.11 under the M47.1 parent 'Other spondylosis with myelopathy,' which carries an Applicable To note for spondylogenic compression of the spinal cord. A Type 1 Excludes bars vertebral subluxation (M43.3–M43.5X9) — if subluxation is also documented, code it separately. Do not use M47.11 if the mechanism is anterior spinal artery compression (M47.011) or vertebral artery compression (M47.021); those are distinct subcategories.
For MS-DRG assignment, M47.11 groups to DRG 551 (Medical back problems with MCC) or DRG 552 (without MCC). CMS LCD A54969 explicitly lists M47.11 as a supporting diagnosis for nerve conduction studies and EMG when myelopathy workup requires electrodiagnostic confirmation. If radiculopathy coexists at a different spinal level, assign the appropriate M47.2x code as an additional diagnosis.
Sibling codes
Other billable codes under M47.1 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01What distinguishes M47.11 from M47.12?
02Can M47.11 and M47.011 be coded together?
03Is a subluxation at C1–C2 included in M47.11?
04Does M47.11 support EMG and nerve conduction study billing?
05What DRGs does M47.11 map to?
06If the patient has both myelopathy at C1–C2 and radiculopathy at C5–C6, how do you code it?
07Is there a 7th-character extension required for M47.11?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M47-/M47.11
- 03cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=54969&ver=51&
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M47.11
- 05outsourcestrategies.comhttps://www.outsourcestrategies.com/blog/icd-10-codes-for-documenting-spondylosis-a-degenerative-condition/
Mira AI Scribe
Mira captures the region (C0–C2 / occipito-atlanto-axial), the neurological exam findings confirming myelopathy (UMN signs, gait, hand function), and MRI findings showing cord compression or T2 signal change at that level. That specificity locks in M47.11 and prevents downcoding to the non-billable M47.1 parent or the wrong regional code.
See how Mira captures M47.11 documentation