ICD-10-CM · Spine

M46.06

M46.06 identifies a disorder of the ligamentous or muscular attachments along the lumbar spine (L1–L5), classifying it as a spinal enthesopathy with inflammatory spondylopathy characteristics.

Verified May 8, 2026 · 4 sources ↓

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

Drawn from CDCCMSAAPCPabau ICD-10

Documentation tips

What should appear in the chart to support M46.06.

Source · Editorial brief grounded in 4 cited references ↓

Specify 'lumbar region' or individual vertebral levels (L1–L5) explicitly — do not rely on a generic 'low back pain' note to support M46.06.
Record imaging findings that indicate an inflammatory process: bone marrow edema on MRI, erosions at entheseal insertions, or periosteal reaction; note the distinction from degenerative osteophytosis.
Document the affected spinal ligaments or muscular attachment sites (e.g., supraspinous ligament, iliolumbar ligament insertions) to substantiate the enthesopathy diagnosis.
If an underlying systemic inflammatory condition (e.g., ankylosing spondylitis, psoriatic arthritis) is present, code that condition first and use M46.06 as an additional code only if it adds specificity not captured by the primary code.
Note prior conservative treatment history (NSAIDs, physical therapy, steroid injections) to support medical necessity for advanced imaging or interventional procedures billed alongside this diagnosis.

Related CPT procedures

Procedure codes commonly billed with M46.06. 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.

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.

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.

72110 $53.44

Radiologic examination of the lumbar spine (lumbosacral) with a minimum of four views, including oblique and/or bending views.

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.

20552 $51.77

Injection(s) into one or two muscles for single or multiple trigger points at a single session.

97530 View procedure details

62323 View procedure details

64483 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M46.06 and adjacent codes.

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

Assigning M46.06 when imaging shows only degenerative disc disease or facet osteoarthritis — those map to M47.816 (spondylosis, lumbar) or M51.x codes, not the inflammatory M46 block.
Using M46.00 (site unspecified) when the note clearly identifies the lumbar spine — always code to the highest specificity the documentation supports.
Confusing M46.06 (lumbar) with M46.07 (lumbosacral) — if pathology is at the L5-S1 junction or involves sacral attachments, M46.07 is more precise.
Omitting a secondary code for the underlying systemic inflammatory arthropathy when one is present, which can trigger payer queries or downcoding on complex cases.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M46.06 applies when a clinician documents enthesopathy — pathology at the bony insertion points of ligaments or muscles — specifically localized to the lumbar region (L1–L5). It sits under M46.0 (Spinal enthesopathy) within the 'Other inflammatory spondylopathies' block, meaning imaging or clinical documentation should support an inflammatory rather than purely degenerative process. If imaging shows only osteoarthritic changes without an inflammatory component, reconsider coding to the appropriate lumbar osteoarthritis or spondylosis code rather than M46.06.

The lumbar-specific 6th character (6) distinguishes this code from adjacent site variants: M46.05 (thoracolumbar), M46.07 (lumbosacral), and M46.00 (site unspecified). Use the most precise anatomic level the documentation supports. If the note spans both lumbar and lumbosacral segments without specifying a primary site, query the provider before defaulting to M46.00.

M46.06 groups into MS-DRG 551 (Medical back problems with MCC) or 552 (Medical back problems without MCC) for inpatient claims. On the outpatient side, it commonly pairs with CPT codes for physical therapy evaluations, spinal injections, and musculoskeletal imaging. No 7th-character extension is required — M-codes do not use encounter-type extensions.

Sibling codes

Other billable codes under M46.0 (laterality / anatomic variants).

M46.00

Spinal enthesopathy, site unspecified

M46.04

Spinal enthesopathy, thoracic region

M46.01

Spinal enthesopathy, occipito-atlanto-axial region

M46.05

Spinal enthesopathy, thoracolumbar region

M46.09

Spinal enthesopathy, multiple sites in spine

M46.07

Spinal enthesopathy, lumbosacral region

M46.03

Spinal enthesopathy, cervicothoracic region

M46.08

Spinal enthesopathy, sacral and sacrococcygeal region

Frequently asked questions

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

01What distinguishes M46.06 from a lumbar spondylosis code like M47.816?

M46.06 targets inflammatory pathology at ligament and muscle insertion points; M47.816 captures degenerative spondylosis. Imaging findings — erosions and bone marrow edema versus osteophytes and disc space narrowing — drive the distinction. Code to whichever process the documentation and imaging primarily support.

02Does M46.06 require a 7th-character extension?

No. M-codes in Chapter 13 do not use 7th-character encounter-type extensions (A/D/S). M46.06 is complete as a 5-character code and is billable without modification.

03Can M46.06 be used as a primary diagnosis for a lumbar steroid injection claim?

Yes. M46.06 is a valid primary diagnosis for spinal injection CPT codes such as 62323 or 64483, provided the medical record documents an inflammatory enthesopathy of the lumbar region and the injection targets that pathology. Confirm payer LCD requirements, as some MACs specify acceptable diagnosis codes for these procedures.

04When should I use M46.07 (lumbosacral) instead of M46.06 (lumbar)?

Use M46.07 when the documented enthesopathy involves the lumbosacral junction or sacral ligamentous attachments. If the provider's note or imaging specifically implicates the L5–S1 level or sacral entheses, M46.07 is more accurate than M46.06.

05Should M46.06 be coded alongside a systemic inflammatory arthritis code?

Only if the lumbar enthesopathy represents a distinct, separately documented condition not fully captured by the primary systemic diagnosis. For example, if the provider documents both ankylosing spondylitis and lumbar enthesopathy as separate clinical entities, dual coding may be appropriate. Follow ICD-10-CM sequencing rules and code the systemic condition first.

06What MS-DRGs does M46.06 map to for inpatient claims?

M46.06 groups to MS-DRG 551 (Medical back problems with MCC) or MS-DRG 552 (Medical back problems without MCC) under MS-DRG v43.0, per the CDC ICD-10-CM Tabular List 2026.

Sources & references

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

01CDC ICD-10-CM Tabular List 2026 — https://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M46-/M46.06
02CMS ICD-10-CM Official Guidelines for Coding and Reporting FY2025 — http://stacks.cdc.gov/view/cdc/158747
03AAPC Codify — https://www.aapc.com/codes/icd-10-codes/M46.06
04Pabau ICD-10 Reference — https://pabau.com/diagnostic-codes/icd-10-code-m4606/

Mira AI Scribe

Mira AI Scribe captures the anatomic site (lumbar, L1–L5), the specific attachment structures involved, and any imaging descriptors that differentiate an inflammatory enthesopathy from degenerative change — MRI bone marrow edema, erosions, or entheseal calcification. This prevents the encounter from falling back to the nonspecific M46.00 or being miscoded to a spondylosis code, both of which can trigger payer denials or medical necessity audits.

See how Mira captures M46.06 documentation