ICD-10-CM · Spine

M24.28

M24.28 classifies a non-traumatic disorder of one or more spinal ligaments that does not fall under a more specific vertebral instability or derangement code.

Verified May 8, 2026 · 5 sources ↓

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

Drawn from CDCICD10DataAAPCCMS

Documentation tips

What should appear in the chart to support M24.28.

Source · Editorial brief grounded in 5 cited references ↓

Name the specific ligament involved (e.g., ligamentum flavum, posterior longitudinal ligament, interspinous ligament) — 'vertebral ligament disorder' alone is sufficient for the code but richer documentation supports medical necessity.
Specify the spinal region (cervical, thoracic, lumbar, sacral) even though M24.28 carries no sub-level specificity; payers and reviewers expect regional documentation.
Distinguish non-traumatic/degenerative etiology from acute injury in the note — acute traumatic ligament injuries require S-codes, not M24.28.
Document how the ligament disorder was identified: MRI signal change, intraoperative finding, or clinical instability pattern — this anchors medical necessity for imaging, injections, or surgical procedures.
If spinal instability is the primary finding, evaluate whether M53.2- (spinal instabilities) is more specific before defaulting to M24.28.

Related CPT procedures

Procedure codes commonly billed with M24.28. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

22840 $668.35

Posterior non-segmental instrumentation placed during spinal surgery, using rods, hooks, or wires that span multiple vertebral levels without anchoring at each intervening segment.

22845 $647.64

Anterior spinal instrumentation placed across 2 to 3 vertebral segments; reported as an add-on to the primary spinal procedure code.

22850 $716.78

Removal of posterior nonsegmental spinal instrumentation — for example, a Harrington rod — without concurrent reinsertion or new hardware placement.

22612 $1,467.64

Posterior or posterolateral lumbar arthrodesis of a single interspace, performed via a posterior approach with bone graft and typically pedicle screw fixation to achieve vertebral segment fusion.

22630 $1,510.72

Posterior interbody arthrodesis of a single lumbar interspace, including laminectomy and/or discectomy performed to prepare the interspace for fusion rather than for decompression.

63047 $1,065.49

Lumbar laminectomy at a single vertebral segment that also includes facetectomy and foraminotomy for decompression of the spinal cord, cauda equina, and/or nerve roots — unilateral or bilateral.

63048 $187.38

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

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.

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.

Common coding pitfalls

The recurring mistakes coders make with M24.28 and adjacent codes.

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

Using M24.28 for acute traumatic spinal ligament tears — those require S-codes (e.g., S13-, S23-, S33-) with 7th-character A for initial encounter, not M24.28.
Defaulting to M24.28 when a more specific spinal code exists — ligamentum flavum ossification maps to M48.1-, posterior longitudinal ligament ossification to M48.1-, and spinal instability to M53.2-; audit M24.28 claims to confirm no more specific code applies.
Omitting the spinal region from the operative or office note, leaving an auditor unable to confirm the vertebral site despite the code being non-lateral by design.
Confusing MS-DRG grouping — M24.28 lands in the tendonitis/bursitis DRG pair (557/558), not a spinal DRG; inpatient coders should verify this is the principal or relevant secondary diagnosis before finalizing DRG assignment.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M24.28 applies when the documented diagnosis is a ligamentous disorder of the vertebral column — such as ligamentous laxity, chronic spinal ligament insufficiency, or degenerative ligament changes — that is not better captured by a more specific spinal code. It sits under the M24.2 (Disorder of ligament) subcategory and is the site-specific code for vertebral involvement within that parent group.

This code is appropriate for conditions like ligamentum flavum hypertrophy when documented as a ligament disorder (rather than a compressive finding coded elsewhere), intersegmental ligament degeneration, or non-traumatic posterior longitudinal ligament pathology not classified under M48- or other spinal chapters. Do not use it for acute spinal ligament sprains or tears — those route to S-code categories with appropriate 7th-character extensions (A/D/S). Do not use it for internal derangement of the knee; that family is excluded at the M24 level.

M24.28 carries no laterality distinction — the vertebral column is treated as a single site. MS-DRG v43.0 groups it under DRG 557 (Tendonitis, myositis and bursitis with MCC) or DRG 558 (without MCC), which affects inpatient reimbursement weight. For outpatient orthopedic coding, pair it with the appropriate spinal CPT procedure code and confirm the operative or clinical note explicitly names the involved ligament and spinal region.

Sibling codes

Other billable codes under M24.2 (laterality / anatomic variants).

M24.20

Disorder of ligament, unspecified site

M24.29

Disorder of ligament, other specified site

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01Does M24.28 require a laterality modifier?

No. The vertebral column has no laterality coding in the M24.2 subcategory. M24.28 is the complete, billable code for any spinal ligament disorder regardless of which side of the spine is involved.

02Can M24.28 be used for an acute spinal ligament sprain documented after a fall?

No. Acute traumatic spinal ligament injuries are coded with S-codes (S13.-, S23.-, S33.-, depending on spinal level) with the appropriate 7th character. M24.28 is reserved for non-traumatic or degenerative ligament disorders of the vertebrae.

03What is the difference between M24.28 and M53.2-?

M53.2- (Spinal instabilities) is the preferred code when documented spinal instability is the primary finding. M24.28 is appropriate when the disorder is specifically characterized as a ligament-level pathology — laxity, degeneration, or insufficiency — without a primary instability diagnosis.

04Which DRG does M24.28 map to under MS-DRG v43.0?

MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or DRG 558 (without MCC). Note this is a soft-tissue DRG pair, not a spinal DRG — relevant for inpatient principal diagnosis sequencing decisions.

05Can M24.28 be used alongside a surgical CPT code for spinal fusion or decompression?

Yes, if the ligament disorder is the documented indication for or finding during the procedure. Pair it with the relevant CPT (e.g., 63047 for laminectomy, 22612 for posterior lumbar fusion) and ensure the operative report names the ligament pathology explicitly.

06Is there a more specific code if the ligamentum flavum is hypertrophied and causing canal stenosis?

Yes. Spinal stenosis with ligamentum flavum hypertrophy typically codes to M48.0- (Spinal stenosis) with the appropriate site character. Use M24.28 only when the ligament disorder is documented independently and does not reduce to a stenosis or instability code.

Sources & references

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

Mira AI Scribe

The Mira AI Scribe captures the specific ligament name, spinal region, mechanism (degenerative vs. traumatic), imaging findings (MRI signal abnormality, hypertrophy, or laxity), and any prior conservative treatment attempts from the encounter note. This prevents downcoding to the unspecified parent M24.20 and blocks audit flags that arise when ligament disorder claims lack anatomical and etiological detail.

See how Mira captures M24.28 documentation