ICD-10-CM · Spine

M46.80

M46.80 classifies a documented inflammatory spondylopathy that is specified by type but lacks documentation of which spinal region is affected.

Verified May 8, 2026 · 4 sources ↓

Status: Billable
Chapter: 13
Related CPT: 10
Region: Spine

Drawn from CDCICD10DataAAPC

Documentation tips

What should appear in the chart to support M46.80.

Source · Editorial brief grounded in 4 cited references ↓

Name the specific inflammatory condition (e.g., enteropathic spondylopathy, undifferentiated spondyloarthropathy) — 'other specified' requires a clinical label, not just 'inflammatory back pain.'
Document why the spinal site is unspecified: e.g., imaging pending, multilevel disease not yet mapped, or patient unable to localize symptoms.
Record imaging findings that confirm an inflammatory process — bone marrow edema, Romanus lesions, syndesmophytes, or MRI signal changes — to distinguish from degenerative spondylosis.
If seronegative spondyloarthropathy is suspected but not fully characterized, document the clinical reasoning; this supports 'other specified' over the unspecified M46.9x.
Note any associated systemic conditions (IBD, psoriasis, reactive arthritis) that contextualize the inflammatory spondylopathy diagnosis, and code those separately as appropriate.

Related CPT procedures

Procedure codes commonly billed with M46.80. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

72148 $191.72

Non-contrast MRI of the lumbar spine used to evaluate disc pathology, spinal stenosis, nerve root compression, and other structural abnormalities without administration of contrast material.

72158 $318.31

MRI of the lumbar spinal canal and its contents performed first without contrast, then repeated after contrast administration for enhanced visualization.

72141 $190.72

MRI of the cervical spinal canal and its contents performed without contrast material.

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.

72020 $23.71

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

20610 $68.81

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

72100 $40.42

Radiologic examination of the lumbosacral spine capturing two or three views, used to evaluate the lumbar vertebrae and sacrum for injury, degeneration, or structural abnormality.

72156 View procedure details

77080 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M46.80 and adjacent codes.

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

Assigning M46.80 when the spinal region is actually documented — if the chart says 'lumbar,' the correct code is M46.86, not M46.80.
Confusing M46.80 with M46.90 (unspecified inflammatory spondylopathy, site unspecified) — M46.80 requires that the condition type be specified; M46.90 is used when neither the type nor the site is defined.
Coding M46.80 for degenerative or mechanical back conditions — imaging showing only osteophytes or disc desiccation does not support an inflammatory spondylopathy code.
Using M46.80 as a default for ankylosing spondylitis or psoriatic spondylitis — both have dedicated codes (M45.x and L40.5x series) that must be used when the specific diagnosis is established.
Failing to add secondary codes for associated systemic diseases (e.g., Crohn's disease, ulcerative colitis) when enteropathic spondylitis is the underlying mechanism — these comorbidities affect medical necessity and authorization.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

Use M46.80 when a provider has identified and documented a specific type of inflammatory spondylopathy — one that does not fit neatly into ankylosing spondylitis (M45), sacroiliitis (M46.1), discitis, vertebral osteomyelitis, or reactive arthropathy — but has not documented or cannot determine the spinal region involved. The 'other specified' designation means the condition is clinically named or described; this is not a catch-all for vague back pain with inflammation.

Imaging must reflect an inflammatory process to support any M46.xx code. Degenerative findings alone point toward M47.xx (spondylosis) or osteoarthritis categories — not M46. If the provider documents a specific spinal region — cervical, thoracic, lumbar, lumbosacral, sacral, etc. — move to the site-specific sibling codes (M46.81–M46.89). M46.80 is valid only when the site is genuinely unspecified or not yet determined.

M46.80 sits one step above M46.9x (unspecified inflammatory spondylopathy, site unspecified) in diagnostic precision — the condition type is known, the site is not. Do not conflate these two. Payers distinguish between 'other specified' and 'unspecified,' and using M46.9x when the condition type has been characterized will flag as under-coded.

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

M46.83

Oth inflammatory spondylopathies, cervicothoracic 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

Frequently asked questions

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

01When is M46.80 the right code versus M46.9x?

M46.80 applies when the type of inflammatory spondylopathy is specified by the provider but the spinal site is not documented. M46.90 is used when neither the condition type nor the spinal site can be determined. If the provider has named or characterized the condition, use M46.80.

02Can M46.80 be used for ankylosing spondylitis?

No. Ankylosing spondylitis has its own category (M45.x) and must be coded there once diagnosed. M46.80 is for inflammatory spondylopathies that are specified but do not fit the defined subcategories within M46, such as sacroiliitis, discitis, or reactive arthropathy.

03What imaging documentation supports M46.80?

MRI findings such as bone marrow edema, Romanus lesions, or inflammatory signal changes support this code. Plain radiograph findings of syndesmophytes or vertebral squaring in an inflammatory pattern also qualify. Degenerative findings alone (osteophytes, disc space narrowing without inflammatory markers) do not support M46.xx codes.

04If the provider documents the lumbar spine is involved, can I still use M46.80?

No. Once a spinal region is documented, the site-specific code applies. For lumbar, use M46.86; for lumbosacral, M46.87; for cervical, M46.82. M46.80 is reserved for cases where the site is genuinely unspecified or not yet determined.

05Should associated systemic conditions be coded separately with M46.80?

Yes. If the inflammatory spondylopathy is enteropathic (linked to IBD), psoriatic, or reactive, code the underlying or associated condition separately. Psoriatic arthropathy with spinal involvement uses the L40.5x series, not M46.8x.

06Is M46.80 valid for FY2026 billing?

Yes. M46.80 is active and billable in the FY2026 ICD-10-CM code set, effective October 1, 2025, per the CDC ICD-10-CM Tabular List 2026.

07What is the difference between M46.8 and M46.80?

M46.8 is the non-billable parent category header for 'Other specified inflammatory spondylopathies.' M46.80 is the billable 5th-character code specifying site unspecified. Always code to the highest level of specificity — bill M46.80 (or a site-specific sibling), never the parent M46.8 alone.

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)
02
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M46-/M46.80
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M46.80
04
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M46-

Mira AI Scribe

Mira's AI scribe captures the provider's named diagnosis for the inflammatory spinal condition, any imaging findings confirming inflammation (MRI signal changes, bone marrow edema, syndesmophytes), the absence of a clearly documented spinal region, and history of associated systemic disease. This prevents downgrade to the non-specific M46.90 and blocks audit flags triggered by coding a degenerative spondylosis code when inflammatory pathology is documented.

See how Mira captures M46.80 documentation