ICD-10-CM · Spine

M48.01

Spinal stenosis localized to the occipito-atlanto-axial region — the articulation between the occiput, atlas (C1), and axis (C2) — where narrowing of the spinal canal compresses neural or vascular structures at the craniocervical junction.

Verified May 8, 2026 · 4 sources ↓

Status
Billable
Chapter
13
Related CPT
10
Region
Spine
Drawn from CDCICD10DataCMSAAPC

Documentation tips

What should appear in the chart to support M48.01.

Source · Editorial brief grounded in 4 cited references ↓

  • Specify the anatomic level by name: 'occipito-atlanto-axial,' 'craniocervical junction,' 'C0-C1,' 'C1-C2,' or equivalent — 'upper cervical stenosis' alone is insufficient for M48.01.
  • Include imaging correlation: MRI or CT myelogram findings documenting canal narrowing, cord compression, or TSLC ratio at C0–C2 strengthen medical necessity and support M48.01 over M48.00.
  • Document the etiology when known (degenerative, rheumatoid, congenital) because payers and clinical quality measures may require additional codes (e.g., M06.08 for rheumatoid arthritis of the vertebral column) linked to the stenosis.
  • Record neurologic findings (myelopathy signs, Lhermitte's sign, upper motor neuron findings, drop attacks) — these directly support medical necessity for advanced imaging, surgical consultation, and intervention CPT codes billed alongside M48.01.
  • If conservative care has been attempted, document the modalities tried (physical therapy, cervical orthosis, chiropractic manipulation) and duration before escalating to procedural or surgical coding, as payers routinely audit this region for step-therapy compliance.

Related CPT procedures

Procedure codes commonly billed with M48.01. 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 M48.01 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

  • Coding M48.01 when the operative or imaging report only specifies 'cervical stenosis' without confirming C0–C2 involvement — the correct fallback is M48.02 (cervical region) or M48.00 (site unspecified).
  • Confusing M48.01 with M48.02 (cervical region, C2–C7): the occipito-atlanto-axial region is anatomically superior and requires explicit documentation of C0, C1, or C2 as the stenotic level.
  • Omitting a co-diagnosis code when the stenosis has a documented underlying cause — rheumatoid pannus, Down syndrome (Q90.x), or Klippel-Feil (Q76.1) should be coded alongside M48.01 per ICD-10-CM etiology/manifestation conventions.
  • Applying a 7th-character extension to M48.01 — M-codes in Chapter 13 do not use the A/D/S encounter extensions; those apply to M48.4x and M48.5x (fracture codes) only.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M48.01 applies when spinal stenosis is documented specifically at the occipito-atlanto-axial region (occiput–C1–C2). This is the uppermost segment of the M48.0 stenosis hierarchy and is anatomically distinct from the subaxial cervical spine (M48.02) or the cervicothoracic junction (M48.03). Use M48.01 only when the provider's documentation explicitly identifies the craniocervical junction as the stenotic level — imaging (MRI or CT myelogram) confirming canal narrowing at C0–C2 is the standard evidentiary basis.

Clinically, stenosis at this level can arise from congenital factors (e.g., atlantoaxial instability in Down syndrome or Klippel-Feil), inflammatory disease (rheumatoid arthritis pannus formation), degenerative changes, or post-traumatic sequelae. Symptoms may include high cervical myelopathy, occipital neuralgia, drop attacks, or quadriparesis — findings that distinguish this region from lower cervical stenosis. If the stenosis spans C0–C2 and extends into the subaxial cervical spine, code the primary/most clinically significant level and consider coding additional levels as appropriate per ICD-10-CM multiple coding guidance.

Do not default to M48.01 when the note simply documents 'cervical stenosis' without specifying the craniocervical junction. Drop to M48.02 (cervical region) or M48.00 (site unspecified) if the exact level is not confirmed. M48.01 has no 7th-character extension requirement — it is a complete, billable code as stated.

Sibling codes

Other billable codes under M48.0 (laterality / anatomic variants).

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 4 cited references ↓

01What anatomic levels does M48.01 cover?
M48.01 covers the occiput (C0), atlas (C1), and axis (C2) — the craniocervical junction. Stenosis beginning at C2–C3 or below codes to M48.02 (cervical region) or lower.
02Can I use M48.01 when the note says 'upper cervical stenosis'?
Only if 'upper cervical' is clearly defined by the provider as the C0–C2 level, ideally with imaging confirmation. Ambiguous documentation defaults to M48.02 or M48.00 — query the provider before assigning M48.01.
03Does M48.01 require a 7th-character extension?
No. M48.01 is a complete, billable code with no 7th-character requirement. The A/D/S extensions apply only to fracture codes M48.4x and M48.5x within the same parent category.
04Should I code M48.01 alongside a rheumatoid arthritis code when RA-related pannus causes the stenosis?
Yes. Code the underlying condition (e.g., M06.08 — rheumatoid arthritis, vertebral) as a secondary or sequencing-appropriate code per ICD-10-CM etiology/manifestation guidance. M48.01 alone does not convey the cause.
05Is M48.01 accepted as a supporting diagnosis for chiropractic services under Medicare?
Yes. CMS LCD article A56273 lists M48.01 explicitly in the group of ICD-10-CM codes that support medical necessity for chiropractic manipulation. Verify that the subluxation is documented and that the manipulated region corresponds to C0–C2.
06What is the correct code if stenosis involves both the occipito-atlanto-axial region and the subaxial cervical spine?
Assign M48.01 for the craniocervical junction level and M48.02 for the cervical region separately. ICD-10-CM does not have a combination code spanning both; code each documented level.
07What imaging is typically needed to support M48.01 on a payer audit?
MRI of the cervical spine with focus on the craniocervical junction is the primary support. CT myelogram is acceptable when MRI is contraindicated. The report should document canal narrowing, cord compression, or signal change at C0–C2 to justify the code's specificity.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

  1. 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
  2. 02
    icd10data.com
    https://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M48-/M48.01
  3. 03
    cms.gov
    https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=56273
  4. 04
    aapc.com
    https://www.aapc.com/codes/icd-10-codes/M48.01

Mira AI Scribe

Mira's AI scribe captures the provider's explicit statement of the stenotic level (occiput, C1, C2, or craniocervical junction), associated neurologic findings (myelopathy, drop attacks, upper motor neuron signs), and imaging summary (MRI/CT canal diameter, cord signal change) from the encounter note. That specificity locks in M48.01 over the nonspecific M48.00, preventing downcoding on audit and satisfying payer medical-necessity criteria for high-cost procedures billed at this level.

See how Mira captures M48.01 documentation

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