ICD-10-CM · Spine

M46.82

Inflammatory spondylopathy of the cervical spine that does not fit a more precisely defined category such as ankylosing spondylitis or reactive arthritis — a residual classification for documented cervical inflammatory spinal disease.

Verified May 8, 2026 · 4 sources ↓

Status
Billable
Chapter
13
Related CPT
10
Region
Spine
Drawn from CDCICD10DataAAPCEcgwaves

Documentation tips

What should appear in the chart to support M46.82.

Source · Editorial brief grounded in 4 cited references ↓

  • The provider must explicitly characterize the condition as inflammatory — not degenerative — in the cervical spine; vague neck pain documentation will not support M46.82.
  • Document the clinical basis for the inflammatory diagnosis: elevated ESR/CRP, MRI signal changes consistent with active inflammation, bone marrow edema on STIR sequences, or rheumatologic consultation findings.
  • Record which cervical levels are involved (e.g., C3–C5) to reinforce the regional specificity coded here and to support associated imaging or intervention codes.
  • If a more specific inflammatory condition is later identified (e.g., psoriatic arthritis, ankylosing spondylitis), update the diagnosis code — M46.82 should not persist once a classifiable etiology is established.
  • Distinguish from cervical disc degeneration (M50.xx) and cervical spondylosis (M47.8xx) in the assessment and plan; payers may question M46.82 if the record also heavily emphasizes degenerative findings.

Related CPT procedures

Procedure codes commonly billed with M46.82. 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 M46.82 and adjacent codes.

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

  • Assigning M46.82 when ankylosing spondylitis of the cervical region (M45.2) is the confirmed diagnosis — M46.82 is a residual code and should not override a more specific option.
  • Using M46.82 for cervical disc degeneration with secondary inflammatory changes; degenerative disc disease codes (M50.xx) take precedence when the primary pathology is degenerative.
  • Failing to check the Excludes1 and Excludes2 notes under M46 before assigning M46.82 — certain conditions such as reactive arthritis and psoriatic spondylopathy have dedicated codes that cannot be reported alongside M46.82 for the same condition.
  • Confusing the cervical region subcode (M46.82) with the cervicothoracic region subcode (M46.83) — confirm documented levels before selecting the digit.
  • Submitting M46.82 without supporting imaging or lab documentation when billing injection procedures, increasing audit exposure.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M46.82 applies to inflammatory conditions of the cervical spine (C1–C7) that are confirmed as inflammatory in nature but cannot be assigned to a more specific code in the M45–M46 block. This includes atypical presentations of spondylitis, cervical enthesitis-related spinal inflammation, or inflammatory arthropathy of the cervical facets and disc spaces when the provider documents an inflammatory — not degenerative — process without specifying a named condition such as ankylosing spondylitis (M45.2) or psoriatic spondylitis (which codes under L40.53).

Before assigning M46.82, confirm you cannot use a more specific code. Ankylosing spondylitis limited to the cervical region goes to M45.2. Reactive arthritis of the spine goes to M02.3x. Discitis not elsewhere classified in the cervical region uses M46.42. M46.82 is the correct landing spot only when the provider's documentation says inflammatory spondylopathy, cervical region — or equivalent clinical language — without naming a classifiable entity.

This code is billable under FY2026 ICD-10-CM and is appropriate as a principal or secondary diagnosis depending on the encounter. When submitted alongside cervical spine imaging, physical therapy, or injection procedures, payers may request supporting documentation that distinguishes the diagnosis from degenerative disc disease (M50.xx codes) — be prepared to reference inflammatory markers, imaging characteristics, or rheumatologic workup in the record.

Sibling codes

Other billable codes under M46.8 (laterality / anatomic variants).

Frequently asked questions

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

01What distinguishes M46.82 from M45.2 (ankylosing spondylitis, cervical region)?
M45.2 is the correct code when ankylosing spondylitis is the confirmed diagnosis. M46.82 is a residual category for inflammatory spondylopathies of the cervical spine that do not meet criteria for any named condition in the M45–M46 block. If AS is documented, use M45.2.
02Can M46.82 be used for cervical spondylosis with inflammation?
No. Cervical spondylosis is degenerative and codes to M47.8xx. M46.82 requires the provider to document a primary inflammatory process. Incidental inflammatory features on a degenerative background do not qualify.
03What CPT codes most commonly pair with M46.82?
Cervical spine X-ray (72040, 72050, 72052), cervical MRI with or without contrast (72141, 72156), and E/M office visits (99213–99215) are the most frequent pairings. Cervical medial branch blocks (64490) or trigger point injections (20552) may also appear depending on management.
04Is there a 7th-character extension required for M46.82?
No. M-codes in Chapter 13 do not use 7th-character injury extensions (A/D/S). M46.82 is a complete, billable code as listed.
05How do I code bilateral involvement or extension into the cervicothoracic region?
Laterality is not relevant for spinal region codes — the cervical region designation covers C1–C7 regardless of side. If involvement extends into the cervicothoracic junction (C7–T1), consider also assigning M46.83 (cervicothoracic region) and discuss with the provider which level is the primary site.
06Does M46.82 require a rheumatology workup before it can be assigned?
ICD-10-CM does not mandate a specific workup for code assignment, but payers often scrutinize inflammatory spine diagnoses. Inflammatory markers, HLA-B27 testing, or MRI findings consistent with inflammation strengthen the record and reduce denial risk.
07Is M46.82 valid for FY2026 ICD-10-CM?
Yes. M46.82 is an active, billable code under FY2026 ICD-10-CM (effective October 1, 2025) with no reported changes to its status or descriptor in the current cycle.

Mira AI Scribe

The Mira AI Scribe captures the provider's explicit inflammatory characterization of the cervical spine condition, relevant imaging findings (MRI STIR signal, bone marrow edema, facet joint changes), lab markers (ESR, CRP, HLA-B27 status), and any rheumatologic consultation notes — all of which anchor M46.82 and prevent payer downcoding to a nonspecific cervical pain or degenerative disc code.

See how Mira captures M46.82 documentation

Related ICD-10 codes

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