ICD-10-CM · Spine

M46.83

M46.83 captures inflammatory spondylopathies of the cervicothoracic spine (C7-T1 junction) that are specified in the clinical record but do not map to a more precise code within the M46 category.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 19
Region: Spine

Drawn from CDCCMSAAPCicd10data.com: 2025

Documentation tips

What should appear in the chart to support M46.83.

Source · Editorial brief grounded in 6 cited references ↓

Specify 'cervicothoracic region' or name the C7-T1 level explicitly in the assessment — do not rely on problem list carry-forward alone.
Identify the type of inflammatory spondylopathy (e.g., psoriatic, reactive, undifferentiated spondyloarthropathy) to satisfy 'other specified' and distinguish from nonspecific dorsopathy codes.
Include supporting imaging findings: MRI or CT evidence of end-plate edema, facet joint inflammation, or enthesitis at the cervicothoracic junction strengthens medical necessity.
Document prior conservative treatment (NSAIDs, physical therapy, corticosteroid courses) and response, particularly when requesting advanced imaging or procedural intervention.
If systemic inflammatory markers (ESR, CRP, HLA-B27) were ordered or resulted, reference them in the note to corroborate the inflammatory — rather than degenerative — diagnosis.

Related CPT procedures

Procedure codes commonly billed with M46.83. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

99213 $95.19

Established patient office or outpatient visit requiring 20–29 minutes of total time or low-complexity medical decision-making.

99214 $135.61

Office visit for an established patient requiring moderate-complexity medical decision making (MDM), or 30–39 minutes of total provider time on the date of service.

99215 $192.39

Highest-level office or outpatient E/M visit for an established patient, qualifying via high-complexity medical decision making or 40–54 minutes of total provider time on the date of service.

72020 $23.71

Single-view radiologic examination of the spine at a specified level.

72040 $39.75

Radiologic examination of the cervical spine capturing two or three views (e.g., AP, lateral, oblique).

72050 $55.11

Radiologic examination of the cervical spine capturing a minimum of four views, used to evaluate alignment, fractures, degeneration, or other structural pathology of the neck.

72052 $62.79

Radiologic examination of the cervical spine using six or more distinct views, the highest-level plain-film cervical series in the CPT spine imaging family.

72070 $33.07

Two-view radiologic examination of the thoracic spine, including AP and lateral projections of the 12 thoracic vertebrae.

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

63045 $1,249.53

Open cervical laminectomy with facetectomy and foraminotomy at a single vertebral level to decompress nerve roots or the spinal cord.

63048 $187.38

Add-on code for laminectomy, facetectomy, and foraminotomy at each additional cervical, thoracic, or lumbar vertebral segment beyond the primary segment.

22551 $1,604.91

Anterior cervical discectomy and fusion (ACDF) at a single interspace, performed through a front-of-neck approach with removal of disc material and arthrodesis of adjacent vertebral bodies.

22600 $1,282.93

Posterior or posterolateral cervical spinal fusion at a single interspace below C2, performed through a posterior approach to achieve bony arthrodesis.

97110 $29.06

Therapeutic exercise billed per 15-minute unit, targeting strength, endurance, range of motion, or flexibility with direct one-on-one patient contact.

97140 $27.72

Skilled, hands-on manual therapy techniques — including joint mobilization/manipulation, manual lymphatic drainage, and manual traction — applied to one or more body regions, billed per 15-minute unit.

72072 View procedure details

77080 View procedure details

62321 View procedure details

97012 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M46.83 and adjacent codes.

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

Using M46.83 when the condition is actually degenerative spondylosis — imaging must support an inflammatory, not purely degenerative, process; default to M47.813 (spondylosis, cervicothoracic) if the chart lacks inflammatory evidence.
Submitting M46.83 with regenerative injection CPT codes (e.g., amniotic/placental-derived products) without checking the applicable LCD — CMS explicitly lists this code as not supporting medical necessity for those procedures.
Defaulting to M46.83 when a more specific M46 code applies — always rule out discitis (M46.43), spinal enthesopathy (M46.03), or ankylosing spondylitis (M45.3) before landing on 'other specified.'
Confusing cervicothoracic (C7-T1, coded as '3' in the regional 6th-character convention) with cervical (M46.82) or thoracic (M46.84) — the region documented in the provider's note must match the code selected.
Applying an injury 7th-character extension to M46.83 — M-codes in this category do not use 7th-character A/D/S extensions; that convention applies to S-codes only.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M46.83 applies when the provider documents a named or described inflammatory spinal condition at the cervicothoracic region — the junction of the lower cervical and upper thoracic spine (C7-T1) — and that condition does not fit a more specific M46 subcategory such as ankylosing spondylitis (M45), discitis (M46.4x), or infective spondylopathy (M46.5x). Examples include psoriatic spondylopathy, reactive spondylopathy, or undifferentiated spondyloarthropathy affecting this transitional zone when the provider explicitly documents cervicothoracic involvement.

The cervicothoracic region designation is meaningful — don't use M46.83 if the documented pathology is confined to the cervical spine (use M46.82) or solely to the thoracic spine (use M46.84). When the inflammatory process spans multiple non-contiguous regions, consider M46.89 (multiple sites). The 'other specified' qualifier requires that the provider's note identify the type or nature of the inflammatory process; if the chart says only 'inflammatory spondylopathy, cervicothoracic' without further specification, that still meets the threshold — 'other specified' means it doesn't fit a named subcategory, not that it's poorly documented.

CMS explicitly lists M46.83 among ICD-10-CM codes that do NOT support medical necessity for amniotic and placental-derived product injections for musculoskeletal indications (LCD A59764, A59766). Verify payer LCD policies before submitting M46.83 with regenerative or biologic injection CPT codes to avoid predictable denials.

Sibling codes

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

M46.87

Oth inflammatory spondylopathies, lumbosacral region

M46.82

Oth inflammatory spondylopathies, cervical region

M46.81

Oth inflammatory spondylopathies, occipt-atlan-ax region

M46.89

Oth inflammatory spondylopathies, multiple sites in spine

M46.88

Oth inflammatory spondylopathies, sacr/sacrocygl region

M46.84

Oth inflammatory spondylopathies, thoracic region

M46.86

Other specified inflammatory spondylopathies, lumbar region

M46.85

Oth inflammatory spondylopathies, thoracolumbar region

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What is the cervicothoracic region for ICD-10-CM coding purposes?

The cervicothoracic region refers to the C7-T1 spinal junction. In the M46.8x series, the regional 6th character '3' consistently designates this zone. Use M46.83 only when the provider's documentation or imaging localizes the pathology to this transitional segment.

02How does M46.83 differ from M46.82 and M46.84?

M46.82 covers the cervical region (above C7-T1) and M46.84 covers the thoracic region (below C7-T1). M46.83 is specific to the cervicothoracic junction itself. If the documentation spans cervical and thoracic regions without specifying the junction, consider M46.89 for multiple sites.

03Can M46.83 be used for ankylosing spondylitis at the cervicothoracic level?

No. Ankylosing spondylitis has its own code series under M45. For cervicothoracic ankylosing spondylitis, use M45.3. Reserve M46.83 for inflammatory spondylopathies that are specified but do not map to M45 or another named M46 subcategory.

04Will M46.83 support medical necessity for biologic or regenerative injections?

No, per CMS LCDs A59764 and A59766, M46.83 is explicitly listed among codes that do NOT support medical necessity for amniotic and placental-derived product injections for musculoskeletal indications. Verify all applicable payer LCDs before pairing this code with regenerative injection procedures.

05Is imaging required to assign M46.83?

ICD-10-CM does not mandate imaging as a coding prerequisite, but AAPC guidance indicates imaging should reflect an inflammatory — not purely degenerative — process before assigning any M46.xx code. Without supportive imaging or labs, the claim may not survive medical necessity review.

06What if the inflammatory spondylopathy involves multiple spinal regions including the cervicothoracic?

If the inflammatory process involves the cervicothoracic region and one or more additional non-contiguous regions, use M46.89 (other specified inflammatory spondylopathies, multiple sites in spine) rather than stacking multiple M46.83-level codes.

07Does M46.83 require a 7th character?

No. M46.83 is a 5-character billable code with no 7th-character extension. The A/D/S encounter-type extensions apply only to injury codes in the S-chapter, not to M-chapter disease codes like M46.83.

Sources & references

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

01CDC ICD-10-CM Tabular List 2026 (FY2026, effective Oct 1, 2025)
02CMS LCD Article A59764: Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Wound
03CMS LCD Article A59766: Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Wound
04CMS LCD Article A56273: Billing and Coding: Chiropractic Services
05AAPC Codify: ICD-10-CM Code M46.83
06icd10data.com: 2025 ICD-10-CM Diagnosis Code M46.8

Mira AI Scribe

Mira captures the provider's explicit region (cervicothoracic / C7-T1), the inflammatory diagnosis type, imaging findings supporting inflammation (MRI Modic changes, facet edema, enthesitis), lab markers (CRP, ESR, HLA-B27), and prior treatment history — preventing a downcode to unspecified dorsopathy or an audit flag for using an inflammatory code without corroborating clinical evidence.

See how Mira captures M46.83 documentation